Abstract: This paper introduces the types of remote starting and stopping pilot circuits of existing motors, the existence of mis-starting, the inability to identify all line faults and the unstable operation of power supply voltage reduction, and proposes an improved optical coupler isolated intrinsically safe pilot circuit. The working principle of the circuit is explained in detail. Experimental results show that the optimized pilot circuit does not have the above problems, and the port output capacitance, inductance and maximum short-circuit current comply with the intrinsic safety regulations.