我想说，您必须按类别名称或类别ID运行查询，使用WP_Query:

$query = new WP_Query( \'cat=cat_ID\', \'posts_per_page\' => 4 );

EDIT: 在编辑中使用get_the_post_thumbnail( $post->ID, \'thumbnail\')相反，小不是默认大小

EDIT2: 最好使用the_title_attribute() 而不是the_title() 如果在HTML属性中：

title="\'.the_title_attribute($post->ID).\'"

以下工作。

<?php
    $args = array(
        \'orderby\' => \'name\',
        \'order\' => \'ASC\'
    );

    $categories = get_categories($args);

    foreach( $categories as $category ) { 
        echo \'<h1><a href="\' . get_category_link( $category->term_id ) . \'" title="\' . sprintf( __( "View all posts in %s" ), $category->name ) . \'" \' . \'>\' . $category->name.\'</a> </h1>\';

        global $post;

        $args = array(
            \'posts_per_page\' => 4,
            \'offset\'=> 0,
            \'category\' => $category->term_id
        );

        $posts = get_posts( $args );

        foreach( $posts as $post ) {
            echo \'
                <a href="\' . $post->guid . \'" title="\' . $post->post_title . \'">
                    \' . get_the_post_thumbnail($page->ID, \'small\') . \'
                </a>
            \';
        }
    } 
?>