这个tax_query 属性是您所需要的。

你可以这样使用它：

$query_args = array(
    \'tax_query\' => array(
        \'relation\' => \'AND\',
        array(
            \'taxonomy\' => \'category\',
            \'field\'    => \'slug\',
            \'terms\'    => array( \'slug-of-category-a\' ),
        ),
        array(
            \'relation\' => \'OR\',
            array(
                \'taxonomy\' => \'category\',
                \'field\'    => \'slug\',
                \'terms\'    => array( \'slug-of-category-b\' ),
            ),
            array(
                \'taxonomy\' => \'category\',
                \'field\'    => \'slug\',
                \'terms\'    => array( \'slug-of-category-c\' ),
            ),
        ),
    ),
);
$query = new WP_Query( $query_args );

或者，利用“IN”操作符（默认情况下在查询术语时用于tax\\u查询）已经作为“Or”条件的事实，您还可以编写：

$query_args = array(
    \'tax_query\' => array(
        \'relation\' => \'AND\',
        array(
            \'taxonomy\' => \'category\',
            \'field\'    => \'slug\',
            \'terms\'    => array( \'slug-of-category-a\' ),
        ),
        array(
            \'taxonomy\' => \'category\',
            \'field\'    => \'slug\',
            \'terms\'    => array( \'slug-of-category-b\', \'slug-of-category-c\' ),
        ),
    ),
);
$query = new WP_Query( $query_args );

这将获得同时位于和中的帖子：

B、C、B和C。有关更多选项，请参阅我链接的文档。