To solve the problem of error accumulation during the calculation and low accuracy of the position location algorithm based on the Received Signal Strength Indication (RSSI) distance measurement in Passive Keyless Enter (PKE) system. A new twice-weighted centroid segmentation algorithm is proposed in this paper. By using transmission theory, the transmission and reflection energy ratio of the radio signal to the car seat was calculated, and an attenuation model of radio signal inside the car was constructed. During the positioning calculation, the twice-weighting factors were introduced, and the position is estimated twice to make the results correct. Simulation results show that the improved algorithm has higher data utilization rate, higher positioning accuracy and smaller positioning error inside the vehicle.