谢邀！

    <?php

    $test = [
        [
            'name'   => 'a',
            'age'    => 12,
            'number' => 11,
            'score'  => 50,
        ],
        [
            'name'   => 'a',
            'age'    => 12,
            'number' => 11,
            'score'  => 30,
        ],
        [
            'name'   => 'b',
            'age'    => 12,
            'number' => 12,
            'score'  => 50,
        ]
    ];
    
    $arr = array();
    foreach($test as $val) {
        $key = $val['name'] . '-' . $val['age'] . '-' . $val['number'];
        $arr[$key]['name']    = $val['name'];
        $arr[$key]['age']     = $val['age'];
        $arr[$key]['number']  = $val['number'];
        $arr[$key]['score']  += $val['score'];
    }
    
    var_dump("<pre>", array_values($arr));die;

兄弟，给你写了个最简单的去重的方法，拿去用吧。

function uniqueArr($arr){
    $returnArr=[];
    
    //分隔符
    $separator="~!#!!#~#!!";
    //排序
    sort($arr);
    
    //去重
    foreach($arr as $value){
        $k=$value['name'].$separator.$value['number'].$separator.$value['age'];
        $returnArr[$k]=[
            'name'=>$value['name'],
            'number'=>$value['number'],
            'age'=>$value['age']
        ];//这里是去重
        $returnArr[$k]['score']+=$value['score'];//这里是累加
    }
    return $returnArr;
}