The invention provides a model test device for a vertical long-time settling character test of a pile foundation. The model test device comprises a test model box, a loading system and a test system. The test model box is a body of the model text device and used for simulating a tested object. The loading system is arranged on the test model box and used for conducting simulating loading on the tested object. An original test object of the test system is arranged on an original tested object of the model box and used for testing the response of the tested object under the dynamic loading action. The test model box, the loading system and the test system are connected to achieve model test of the long-time settling character test of the pile foundation. The invention further discloses an application of for simulating and testing the vertical long-time settling character in different soil bodies under different train loading actions. By means of the model test device and the application, vertical power loading of a model pile can be achieved, stress strain of a pile body under the dynamic loading action can be tested, and the contact condition of the pile soil interface in a model accords with the actual situation.