1,'pid'=>0,'name'=>'一级11'), array('id'=>2,'name'=>'一级12'), array('id'=>3,'pid'=>1,'name'=>'二级21'), array('id'=>4,'pid'=>3,'name'=>'三级31'), array('id'=>5,'name'=>'二级22'), array('id'=>6,'name'=>'三级32'), array('id'=>7,'pid'=>6,'name'=>'四级41'), ); $i = 0; function formatTree($arr,$pid = 0){ $tree = array(); $temp = array(); global $i; if($arr){ foreach($arr as $k=>$v){ if($v['pid'] == $pid){// $temp = formatTree($arr,$v['id']); $temp && $v['son'] = $temp; $tree[] = $v; } } } return $tree; } print_r(formatTree($items));

$items = array( 1 => array('id' => 1,'pid' => 0,'name' => '一级11'), 2 => array('id' => 2,'pid' => 1,'name' => '二级21'), 3 => array('id' => 3,'name' => '二级23'), 4 => array('id' => 4,'pid' => 9,'name' => '三级31'), 5 => array('id' => 5,'pid' => 4,'name' => '四级43'), 6 => array('id' => 6,'name' => '三级32'), 7 => array('id' => 7,'name' => '四级41'), 8 => array('id' => 8,'name' => '四级42'), 9 => array('id' => 9,'name' => '二级25'), 10 => array('id' => 10,'pid' => 11,'name' => '二级22'), 11 => array('id' => 11,'name' => '一级12'), 12 => array('id' => 12,'name' => '二级24'), 13 => array('id' => 13,'name' => '四级44'), 14 => array('id' => 14,'name' => '二级26'), 15 => array('id' => 15,'pid' => 8,'name' => '五级51'), 16 => array('id' => 16,'name' => '五级52'), 17 => array('id' => 17,'name' => '五级53'), 18 => array('id' => 18,'pid' => 16,'name' => '六级64'), ); print_r(genTree($items));