This paper presents the design of a smart parking managemnet system which consists of non-stop automatic gate guard payment system and parking spot detection system. We first briefly introduce RFID technique and discuss its operating principles. Then we propose a design for controlling and managing parking system using RFID technique which is able to automatically calculate the parking fee of vehicles and show the number of unoccupied parking space in the screen at the entrance. Finally, we simulated the anti-interference ability of Manchester coding and decoding in this RFID system, the radio-frequency interference circuit of RF tag and the transmission and receiving module of the RF reader using the simulation software Simulink.