Object of class stdClass could not be converted to string in

I solved it. Just change:

foreach( $poster_id as $index => $posterss_id ) {
    global $post;
    $post = get_post( $posterss_id->ID );
    $linker_sluger = $link_sluger[$index]->guid; 
    /* ... */
}

Full Solution:

global $wpdb;

$poster_id      = $wpdb ->get_results( "SELECT ID from wp_posts WHERE post_status="publish" AND post_type="post" AND post_content LIKE '%[gallery%' ORDER BY ID DESC" );
$link_sluger    = $wpdb ->get_results("SELECT guid FROM wp_posts WHERE post_name LIKE 'albums%' ORDER BY guid DESC");

foreach( $poster_id as $index => $posterss_id ) {

    global $post;
    $post = get_post($posterss_id->ID);
    $linker_sluger= $link_sluger[$index]->guid;

    if( has_shortcode( $post->post_content, 'gallery' ) ){

        echo'<div class="single-album home-last-gallery col-md-4 col-sm-12"> <a href="'.$linker_sluger.'">';
        echo na_get_gallery_image_urls($posterss_id->ID, $linker_sluger); 
        echo '</a></div>';

    }

}