Indirect time of flight (iTOF) camera has a wide application prospect in the field of three-dimensional environmental perception. According to the imaging principle of iTOF camera, its imaging quality is closely related to the exposure time. When the exposure time is too large causing the camera to work in the nonlinear area, the depth information of the solution will also introduce additional biases and thereby affecting the accuracy of the measurement results. In order to further improve the application accuracy of time-of-flight camera, according to the optical imaging mechanism of time-of-flight camera, a method was put forward to measure the performance parameters of time-of-flight camera. Through experiments and calculations, the global system gain and other performance parameters of time-of-flight depth camera were indirectly obtained, then the corresponding curves between distance and camera output gray value could be obtained by substituting them into the optical imaging model of time-of-flight camera, and the necessity of measuring related performance parameters was verified by experimental results. The relative error between modeling and experimental results can be within 20%, and the average relative error is 0.16%. These performance parameters and simulation models are used to guide the integration time selection of iTOF cameras when used in different scenarios, which can effectively solve the problem of reducing distance measurement accuracy due to the introduction of non-linear errors by improper use.