我在这里找到了答案：Customizing wp-activate.php

这确实是一种变通方法，但效果很好。

Step 1创建名为“激活”的新页面

Step 2创建名为“模板激活”的新模板。php”，并添加以下代码：

**Template (template-activate.php)**
<?php
/**
 * Template Name: Activation
 *
 */

/**
 * Confirms that the activation key that is sent in an email after a user signs
 * up for a new blog matches the key for that user and then displays confirmation.
 *
 * @package WordPress
 */

if ( !is_multisite() OR (empty($_GET[\'key\']) && empty($_POST[\'key\'])) ) {
    wp_redirect( site_url( \'/wp-login.php?action=register\' ) );
    die();
}

if ( is_object( $wp_object_cache ) )
    $wp_object_cache->cache_enabled = false;

// Fix for page title
$wp_query->is_404 = false;

/**
 * Fires before the Site Activation page is loaded.
 *
 * @since 3.0
 */
do_action( \'activate_header\' );

/**
 * Adds an action hook specific to this page that fires on wp_head
 *
 * @since MU
 */
function do_activate_header() {
    /**
     * Fires before the Site Activation page is loaded, but on the wp_head action.
     *
     * @since 3.0
     */
    do_action( \'activate_wp_head\' );
}
add_action( \'wp_head\', \'do_activate_header\' );

get_header();

//theme specific (CoWorker)
get_template_part( \'include/content\', \'head\' );
?>

<?php
        $key = !empty($_GET[\'key\']) ? $_GET[\'key\'] : $_POST[\'key\'];
        $result = wpmu_activate_signup($key);
      $siteurl = site_url();
      $lostpassword = $siteurl.\'/lostpassword\';
        if ( is_wp_error($result) ) {
            if ( \'already_active\' == $result->get_error_code() || \'blog_taken\' == $result->get_error_code() ) {
                $signup = $result->get_error_data();
                ?>
                <h2><?php _e(\'Your account is now active!\'); ?></h2>
                <?php
                echo \'<p class="lead-in">\';
                if ( $signup->domain . $signup->path == \'\' ) {
                    printf( __(\'You may now <a href="%1$s">log in</a> to the site using your chosen username of <strong>&#8220;%2$s&#8221;</strong>.</p><p>Please check your email inbox at <strong>%3$s</strong> for your password and login instructions.</p></p>If you do not receive an email, please check your junk or spam folder. If you still do not receive an email within an hour, you can <a href="%4$s">reset your password</a>.</p>\'), $siteurl.\'/login\', $signup->user_login, $signup->user_email, $lostpassword );
                } else {
                    printf( __(\'Your site at <a href="%1$s">%2$s</a> is active. You may now log in to your site using your chosen username of <strong>&#8220;%3$s&#8221;</strong>.</p><p>Please check your email inbox at %4$s for your password and login instructions. If you do not receive an email, please check your junk or spam folder. If you still do not receive an email within an hour, you can <a href="%5$s">reset your password</a>.\'), \'http://\' . $signup->domain, $signup->domain, $signup->user_login, $signup->user_email, $lostpassword );
                }
                echo \'</p>\';
            } else {
                ?>
                <h2><?php _e(\'An error occurred during the activation\'); ?></h2>
                <?php
                echo \'<p>\'.$result->get_error_message().\'</p>\';
            }
        } else {
            extract($result);
            $url = get_blogaddress_by_id( (int) $blog_id);
            $user = get_userdata( (int) $user_id);
         $username = $user->user_login;
         $useremail = $user->user_email;
            ?>
            <h2><?php _e(\'Your account is now active!\'); ?></h2>

            <div id="signup-welcome">
              <p class="view"><?php printf( __(\'You may now <a href="%1$s">log in</a> to the site using your chosen username of <strong>&#8220;%2$s&#8221;</strong>.</p><p>Please check your email inbox at <strong>%3$s</strong> for your password and login instructions.</p></p>If you do not receive an email, please check your junk or spam folder. If you still do not receive an email within an hour, you can <a href="%4$s">reset your password</a>.</p>\'), $siteurl.\'/login\', $username, $useremail, $lostpassword ); ?></p>
         </div>
            <?php
        }
    ?>

<script type="text/javascript">
    var key_input = document.getElementById(\'key\');
    key_input && key_input.focus();
</script>

<?php
//theme specific (CoWorker)
get_template_part( \'include/content\', \'foot\' ); 

get_footer();
?>  

Step 3 创建一个名为“自定义激活电子邮件”的新插件文件。php\'

<?php 
/*
Plugin Name: Custom Activation Email
Plugin URI: YOUR URL
Description: Plugin to customize the automated user account activation email
Author: ME
Version: 1.0
Author URI: YOUR URL
*/
    add_filter( \'wpmu_signup_user_notification\', \'kc_wpmu_signup_user_notification\', 10, 4 );
    function kc_wpmu_signup_user_notification($user, $user_email, $key, $meta = \'\') {
        $sitename = get_bloginfo( \'name\' );
        $blog_id = get_current_blog_id();
        // Send email with activation link.
        $admin_email = get_option( \'admin_email\' );
        if ( $admin_email == \'\' )
            $admin_email = \'support@\' . $_SERVER[\'SERVER_NAME\'];
        $from_name = get_option( \'blogname\' ) == \'\' ? $sitename : esc_html( get_option( \'blogname\' ) );
        $message_headers = "From: \\"{$from_name}\\" <{$admin_email}>\\n" . "Content-Type: text/plain; charset=\\"" . get_option(\'blog_charset\') . "\\"\\n";
        $message = sprintf(
            apply_filters( \'wpmu_signup_user_notification_email\',
                __( "Hi %s,\\n\\nThank you for registering with %s.\\n\\nTo activate your account, please click the following link:\\n\\n%s\\n\\nYou will then receive an email with your login details." ),
                $user, $user_email, $key, $meta
            ),
            $user,
            $sitename,
            site_url( "activate/?key=$key" )


        );
        // TODO: Don\'t hard code activation link.
        $subject = sprintf(
            apply_filters( \'wpmu_signup_user_notification_subject\',
                __( \'%3$s - Activate your account\' ),
                $user, $user_email, $key, $meta
            ),
            $from_name,
            $user,
            $sitename
        );
        wp_mail($user_email, $subject, $message, $message_headers);

        return false;
    }
?>

Notes我正在使用“Theme My Login”插件，因此更改了/Login和/lostpassword的链接。我选择作为插件执行步骤3，而不是添加到主题的功能中。php，因为我似乎不是那样工作的。