您可以使用类似的

<?php
//Post we need to update
$id = 37;

 $custom_field = get_post_meta( $id, \'custom_field_key\', true );
// Update post 37
  $mg_post = array(
      \'ID\'           => $id,
      \'post_content\' => $custom_field,
  );

// Update the post into the database
  wp_update_post( $mg_post );

//Delete the custom field
delete_post_meta( $id, \'custom_field_key\' );
?>