<input type="text" ng-model="inputValue">
<button ng-click="updateValue()">点击更新</button>

angular.module('myApp', [])
  .controller('myController', function($scope) {
    $scope.inputValue = ''; // 初始化输入框的值

    $scope.updateValue = function() {
      $scope.inputValue = '新的值'; // 更新输入框的值
    };
  });

<div ng-app="myApp" ng-controller="myController">
  <input type="text" ng-model="inputValue">
  <button ng-click="updateValue()">点击更新</button>
</div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.8.2/angular.min.js"></script>