The invention relates to a device and method for horizontal stress test of spiral ground anchors. The device is composed of a test bracket, a loading device and a measuring device. The test bracket iscomposed of an upper bearing beam, an upper support cross beam, a reaction beam, a tension transfer column, a bottom bearing beam, a bottom support cross beam, a vertical metallic channel column anda locating beam; the loading device is composed of a jack, a cushion block, a top support plate, steel strands and matched clips, and a power transmission line shaft; and the measuring device comprises a pressure sensor, a displacement meter base and a datum beam. The method for vertical and horizontal test of the spiral ground anchors comprises the steps of driving the spiral ground anchors, fixing the bracket and the sensor, preloading, fixing the measuring device, applying the load, recording the test data and so forth, and the displacement of the pile heads of the spiral ground anchors under the action of different loads is obtained, so that the uplift bearing capacity of the spiral ground anchors is judged.