<form action="{:U('index/upload')}" method="post" enctype="multipart/form-data">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 文件上传：<input type="file" name = "test[]">
 <input type="submit" value = "提交">
</form>

<?php
namespace Home\Controller;
use Think\Controller;
class IndexController extends Controller {
 public function index(){
  $this->display();
 }
 public function upload(){
  if(IS_POST){
   $config = array(
    'maxSize' => 3145728,
    'rootPath' => './Uploads/',
    'savePath' => '',
    'saveName' => array('uniqid', mt_rand(1,999999).'_'.md5(uniqid())),
    'exts'  => array('jpg', 'gif', 'png', 'jpeg'),
    'autoSub' => true,
    'subName' => array('date','Ymd'),
   );
   $upload = new \Think\Upload($config);// 实例化上传类
   $info = $upload->upload();
   if(!$info) {
    $this->error($upload->getError());
   }else{
    foreach($info as $file){
     echo $file['savepath'].$file['savename'];
    }
   }
  }else{
   $this->display();
  }
 }
}

$config = array(
    'maxSize' => 3145728,
    'rootPath' => './Uploads/',
    'exts'  => array('jpg', 'gif', 'png', 'jpeg'),
    'autoSub' => true,
    'subName' => array('date','Ymd'),
    'saveRule' => '',
   );

$config = array(
    'maxSize' => 3145728,
    'rootPath' => './Uploads/',
    'saveName' => array('uniqid', mt_rand(1,999999).'_'.md5(uniqid())),
    'exts'  => array('jpg', 'gif', 'png', 'jpeg'),
    'autoSub' => true,
    'subName' => array('date','Ymd'),
   );