show all custom posts types in home page

add_action( 'pre_get_posts', 'add_my_post_types_to_query' );

function add_my_post_types_to_query( $query ) {
  if ( is_home() && $query->is_main_query() )
    $query->set( 'post_type', 'any' );
  return $query;
}

refer to http://codex.wordpress.org/Class_Reference/WP_Query#Type_Parameters