这是你的解决办法。更改sku的每页post参数和post meta值(（未测试）
https://www.themelocation.com/how-to-updateadd-sku-of-all-products-in-woocommerce/

add_action( 'init', 'update_sku', 10, 1);

function update_sku( $sku ){

   $args = array(

           'post_type' => 'product',

          'posts_per_page' => -1

           );

   $i=0;

   $loop = new WP_Query( $args );

   if ( $loop->have_posts() ) {

       while ( $loop->have_posts() ) : $loop->the_post();

           $random_sku = mt_rand(100000, 999999);

           update_post_meta($loop->post->ID,'_sku','');

           $i++;
       endwhile;

   } else {
       echo __( 'No products found' );
   }
   wp_reset_postdata();
}