Abstract: An optimized three-stage fuzzy controller is presented for urban traffic signals (OTSFC) and its Paramics-based simulation. Based on the analysis of uncertainty of traffic flow, a three-stage fuzzy controller structure is proposed by taking traffic demand intensity, phase optimization, and extension time of current green phase into account. Then, overlap phase is introduced to design the mechanism of phase optimization, and a three fuzzy control algorithm is developed followed by the basic principles of traffic signal control. Finally, the COM-based hybrid programming is employed to develop Paramics-based simulation platform of the OTSFC. The proposed method is tested on a blackspot isolated intersection in Shenzhen under various traffic conditions. Simulation results have demonstrated the potential of the developed OTSFC in control performance and the rapid response ability to the uncertainty of traffic flow.