The invention discloses a moisture migration test device and method under the combined action of a temperature and a humidity field, and solves the problem that only a humidity field is analyzed and the accuracy of a test result is influenced in the prior art; the moisture migration test device is simple in structure, convenient to operate and capable of obtaining the moisture migration rule and strength evolution under the combined action of the temperature and the humidity, and the scheme is as follows: the moisture migration test device under the combined action of the temperature and the humidity field comprises a water tank, a sample barrel and a thermostat, wherein colored water can be contained in the water tank; a soil sample can be arranged in the sample barrel, the bottom of thesample barrel is inserted into the water tank, and the bottom of the sample barrel can be immersed in the colored water in the water tank; a humidity sensor and a bending element, which can be inserted into the soil sample, are arranged on the side part of the sample barrel; and the thermostat is arranged at the top of the sample barrel, and a heating element is arranged in the thermostat.