The temperature fluctuation of the laser will cause the change of its output characteristics. In order to achieve the accurate measurement of the detection system, it is necessary to explore the influence of temperature change on the output characteristics. In this paper, the effects of different temperature gradients on the internal parameters of the laser under transient conditions are studied, including the photon density, carrier density, threshold current, photoelectric delay, relaxation phenomenon and output power characteristics.Simulink is used in experimental simulation to build a simulation model. Starting from the rate equation, the gain coefficient related to temperature change and the influence of transparent carrier are introduced to obtain the parameter change under temperature change. The experimental results show that the temperature change has a great impact on the internal performance of the laser, which will weaken the detection accuracy. In order to reduce the error caused by the temperature change, the corresponding temperature control circuit should be used.