Why I not get value from $form_state['values']['field_form_name'] I created module_templat with code:

&lt;?php

 function module_template_menu(){
    $items = array();
    $items['them-noi-dung'] = array(
        'title' =&gt; t('Khai báo hóa chất'),
        'page callback' =&gt; 'drupal_get_form',
        'page arguments' =&gt; array('module_template_select_form',2),
        'access callback' =&gt; true,
    );
    return $items;
    }

function module_template_select_form($form, &amp;$form_state){
    $form = array();
    $form['select'] = array(
        '#type' =&gt; 'radios',
        '#title' =&gt;'Lựa chọn hình thức khai báo',
        '#options' =&gt; array('0'=&gt;t('Khai báo lần đầu'), '1'=&gt;t('Đã từng khai báo')),
        '#default_value' =&gt; '0', 
    );
    $form['ma_so_thue'] = array(
    '#type' =&gt; 'textfield',
    '#size' =&gt; '20',
    '#title' =&gt; 'Vui lòng nhập vào Mã Số Thuế',
    '#states' =&gt; array(
        'visible' =&gt; array(':radio[name="select"]' =&gt; array('value'=&gt;'1'),  
                    ),
            ),
    );
    $form['submit'] = array(
        '#type' =&gt; 'submit',
        '#value' =&gt; t('Tiếp tục'),
    );
    return $form;
    }

function module_template_select_form_submit($form, &amp;$form_state) {
    $select = $form_state['values']['select'];
    $masothue = $form_state['values']['ma_so_thue'];
    if(isset($select)){
        $masothue = $form_state['values']['ma_so_thue'];
        $form_state['redirect'] = 'node/add/khai-bao-hoa-chat';
        }
    }


function module_template_form_alter( &amp;$form, &amp;$form_state, $form_id ){
    $masothue = $form_state['values']['ma_so_thue'];
    if ($form_id == 'khai_bao_hoa_chat_node_form') {
        $form['field_ten_to_chuc']['und'][0]['value']['#default_value']= $masothue;
        }
    }
function module_template_theme($existing, $type, $theme, $path) {
    $items = array();
    $items['khai_bao_hoa_chat_node_form'] = array(
        'render element' =&gt; 'form',
        'template' =&gt; 'khai-bao-hoa-chat',
        'path' =&gt; drupal_get_path('module', 'module_template'),
        );  
    return $items;
    }


Why I  can not get value of $form_state['value']['ma_so_thue'] in module_template_form_alter(&amp;$form, &amp;$form_state, $form_id) when form submited?
The code you are showing is wrong for two reasons:


hook_form_alter() is invoked for every form Drupal is showing; this includes Drupal core forms, as well as forms implemented by third-party modules. It is not invoked for the forms of your own module. So, you first need to check for which form the hook is being invoked, then you can access the form fields the form of your module is using.
hook_form_alter() is not invoked when the form is submitted, but before the form is rendered. So you cannot use $masothue = $form_state['values']['ma_so_thue']; there. You need to add a new submission handler from hook_form_alter(), and in that submission handler you can get the submitted values, but then you cannot alter the default value for a form field in a submission handler.