Abstract: For the complex indoor environment, the existing RFID target tracking method is easily affected by multipath effect and non-line of sight, The typical particle filter algorithm is used to estimate the low precision, An improved particle filter algorithm is proposed. The algorithm utilizes the unscented Kalman filter to construct the importance distribution function of the particle filter, so that the importance distribution function is integrated into the latest observation information. The state equation of the dynamic target is established according to the motion model, and the observation equation is established by taking the signal strength received by the reader as the observation value. Compared with other filtering algorithms, the simulation results show that the algorithm effectively improves the accuracy of target tracking and enhances the stability of the target tracking system.