A short-circuit protection circuit applied in intelligent high side power switch was presented. It included output short-circuit detecting circuit, delay signal generating circuit and gate-source voltage limiting circuit. NMOS transistors were used as the power transistors, so the circuit was still in the safe operating area when the circuit was short, and the reliability of high side power switch were improved. The short-circuit protection circuit was simulated in 0.6 μm HV SOI process. The simulation results showed that the power transistors were keeping in the safe operating area under the condition of hard switch fault and load short-circuit.