自定义查询> post__in => $ page_id（多页未显示/只显示1页）

<?php
global $redux_demo; 
$page_id = $redux_demo[input_id];

$query_page = new WP_Query(array(
    'post_type'=>'page',
    'post__in'=>array($page_id)
));
?>

its show just single page, not multiple pages.

var_dump($page_id); // output '192, 185, 188, 150'    // include = 'punctuation'

if manual input = array(192, 185, 188, 150) show selected pages.

How can I fixed this problem $page_id ???

The post__in parameter expects an array of IDs, and you're passing it a string (see WP_Query - Post & Page Parameters for more details.

So, you need to convert $redux_demo[input_id] into an array first:

global $redux_demo;

// Convert input into an array, and remove whitespaces
$page_id = array_map( 'trim', explode(',', $redux_demo['input_id']) );

$query_page = new WP_Query(array(
    'post_type' => 'page',
    'post__in' => $page_id
));

Also, it seems you're missing some quotes here: $redux_demo[input_id]. Shouldn't it be $redux_demo['input_id'] instead?