According to the non-reciprocal phenomenon of acousto-optic devices,the light intensity attenuation affects diffraction efficiency and reduces the efficiency of laser heterodyne interference.A method based on acousto-optic devices at 100 MHz of laser heterodyne interferometer under the impact of non-reciprocal effect is proposed.By performing the beam diffraction experiments,the method,which combines an aperture and TeO2 crystal,applies optical power measurement to obtain non-reciprocal value of the device and analyzes distribution of the diffraction efficiency under different driving frequencies.A 100 MHz acousto-optic modulator(AOM) is used in laser heterodyne interferometer experiment to determine the influence of non-reciprocal effect on the heterodyne IF signal.Experiments reveal that in the cases of AOM center frequency at 100-105 MHz,utilizing the non-reciprocal effect the heterodyne signal power from +13 dBm to +21 dBm can be achieved,and the IF signal has 7.69 dB gain.The RF in acousto-optic devices at 100 MHz presents the non-reciprocal effect,and the non-reciprocal effect can effectively improve the efficiency of laser heterodyne interferometer under laboratory conditions.