The invention provides an interferometer for environment temperature compensation. The interferometer comprises an optical splitter, wherein the optical splitter comprises an optical split film; an incidence beam is split into a first beam and a second beam at the splitting position of the optical split film; the first beam is transmitted by a first interference arm and is reflected to the optical splitter through a first light path, and the second beam is transmitted by a second interference arm and is reflected to the optical splitter through a second light path; the first beam and the second beam are outputted from the optical splitter after the first beam and the second beam are subject to interference at the optical split film of the optical splitter; the incidence beam carries phasemodulation data; the first interference arm is provided with a heater to change the path of the first light path to ensure the difference of the paths of the first light path and the second path is related to the transmission velocity of an optical signal. The interferometer is characterized in that at least one interference arm is provided with a temperature compensator to compensate the phase drift brought by environment temperature. The interferometer has the advantages that drift generated by the environment temperature can be compensated by the temperature compensator, so that the interferometer has a more stable working state.