As CMOS technology scales down, the design of ESD protection circuits becomes more challenging. There are some disadvantages for the actual power clamp circuit. In this paper, an optimization ESD power clamp circuit is proposed. The new clamp circuit adopts the edge triggering True Single Phase Clocked Logic (TSPCL) D flip-flop to turn on and time delay, it has the advantage of dynamic transmission structure. By adding a leakage transistor of small size, the clamp circuit can turn off effectively. By changing the W/ L ratio, the clamp can safely protect the gate of ESD power clamp devices from thermoelectric breakdown. The results show that the circuit can reduce the false triggering and power supply noise more effectively, it can be widely used in high-speed integrated circuits. The proposed structure has the advantages of low power and low cost, and can be used to the system-level ESD protection.