Objective To design a kind of intelligent control system of pulse current cathodic protection for oil well casing, realize the intelligent operation of power supply, and make sure that the cathodic protection of oil well casing pulse current is in the best condition. Methods Three-level closed-loop control strategy was adopted to realize the adaptive regulation of power supply. The advanced processing algorithm was used to deal with the output current, output voltage and casing potential, to determine the protective effect of pulse current cathodic protection, and output the corresponding PWM control signal to achieve real-time control of the power supply. Results A pulse current cathodic protection system of the oil well casing was simulated in the PVC insulated sink of 5. 0 m×0. 5 m×0. 5 m. This control system could control the pulse current with independently adjustable output frequency, amplitude and duty cycle, and the protection potential of the steel reached -0. 85 V. Conclusion This control system could realize the intelligent operation of power supply of pulse current cathodic protection for oil well casing, with advantages of low cost, high reliability, perfect function, and convenient operation.