Abstract: Hydro-viscous speed clutch is a central control element of the driver system. And because of nonlinearities and hysteresis of the clutch, the setting of control parameters will significantly impact on the performance of the speed control system. In this paper, a tuning method of PID controller parameters for the closed-loop speed control system was investigated to be applicable for a hydro-viscous speed clutch of certain vehicle temperature control system. Employing a two-storey optimized control framework, the resulting model from identification was found to be able to complete the self-tuning of control parameters. Simulation and experimental results show that this self-tuning method can get a group of parameters in terms of a desired performance index, which can reach the balance of dynamic characteristics, stability and anti-jamming in closed-loop system.