The cathodic protection rectifier (also called potentiostat or transformer-rectifier) is the core power supply of the impressed current cathodic protection (ICCP) system, widely used in anti-corrosion works for all kinds of steel structures. Its core function is to accurately convert industrial AC into controllable DC, and by intelligently adjusting output voltage and current, keep the structure potential within the standard protection range (-850 mV to -1200 mV vs CSE), fundamentally suppressing electrochemical corrosion, effectively extending the service life of equipment, pipelines and steel structures, and greatly reducing O&M and refurbishment costs.