Abstract: Rod position measurement sensor is the key equipment of the nuclear heating reactor to obtain the control rod position during the rod stepping and reactor scram operations, and the sensor’s accuracy and reliability are directly related to the safety of the reactor. For the double helix capacitance rod position measurement sensor, the static characteristic experiment of the sensor was completed and the calculation model was established by using the finite element analysis method. The calculated results of the model are in good agreement with the experimental results. And on the basis, the finite element analysis method and orthogonal test method were used to analyze the influence of plate angle, plate pitch, thickness of ceramic tube and other design parameters on the eccentricity performance of the sensor, and the optimal combination of design parameters was obtained. The results show that the eccentricity error of the sensor can be reduced by reducing the plate angle, increasing the plate pitch, increasing the thickness and reducing the relative permittivity of the ceramic tube, and the parameter combination obtained by the orthogonal test method can meet the requirement that without losing step in rod position measurement. The research results lay the foundation for the design and optimization of double helix capacitance rod position measurement sensor.