Abstract: This paper studies the influence of a dielectric layer with a millimeter-level cylindrical structure on the sensitivity of a flexible capacitive pressure sensor. The designed sensor is prepared by pouring and transferring process using a polytetrafluoroethylene mold, and the obtained film dielectric layer is neatly arranged and has a good shape. The influence of the cylindrical dielectric layer structure on the sensitivity of the sensor is studied by a combination of simulation and experiment. According to the simulation results, the sensitivity of the sensor is increased from 4.8×10^-3kPa^-3 to 1.2×10^-2kPa^-1. The specific experimental results show that the sensitivity of the sensor is increased from 1.2×10^-5 kPa^-1 to 1.2×10^-4 kPa^-1. Both simulation and experimental results show that the dielectric layer of the millimeter-scale cylindrical structure can effectively improve the sensitivity of the flexible capacitive pressure sensor.