The capacitive grating sensors with dedicated integrated chips are widely used in a variety of measurement devices, and the design has a significant impact on the overall system performance of the sensor under the same materials and processes. This article analyzes the structural principles and working characteristics of the capacitive grating sensor. And for the problem that the chip input signal cannot be directly given by the chip input signal in the simulation design process, a segmented transmission function of the capacitor and displacement is designed. We need to use the Verilog-A language to model the capacitive grating sensor, and simulate the correctness of the model on the Cadence Spectre, which improves the simulation speed and makes the simulation and practice more fit.