Abstract: In order to reduce the temperature sensitivity of the zero drift in four-frequency differential laser gyro (FFDLG), the mathematical compensation model and the thermal design of the installation structure were studied. The relationship between zero drift and temperature of the FFDLG was studied by high and low temperature tests. In the first test, the FFDLG was fixed in the shielding box by an ordinary copper support. Due to the asymmetry of the temperature changes in the two discharge branches, the temperature change rate was a significant term of the mathematical compensation model. In the second test, a special copper support was designed to make the temperature in the two discharge branches change symmetrically, so the importance of temperature change rate in the mathematical compensation model was greatly reduced. After the support was improved, the root mean square (RMS) of residual bias after compensation decreased from 0.018 Hz to 0.01 Hz. Even if only a polynomial of temperature was used in the compensation model, an RMS of residual bias of 0.012 Hz could be achieved. The results show that:when designing FFDLG system, the thermal design of the installation structure can improve the compensation effect of the mathematical model. Temperature compensation is an effective method to improve the accuracy of the FFDLG. An FFDLG with an RMS of residual bias of 0.013 ()/h in the range of -40-60℃ was obtained after improvement in the installation structure and temperature compensation.