Electrode boiler safety protection device is a widely used thermal oil boiler in domestic small industrial boilers (below 4t/h) boiler emergency shutdown, high and low water level control report, water level remote display and automatic water refill device. It consists of an electrode sensor for an electrode type boiler and an electrical control. The electrode sensor uses the different conductance (resistance) of water and steam to convert the water level parameter into an electrical signal output, and the electronic control part converts the electrical signal output by the sensor into the corresponding water level display, control and alarm. Therefore, in theory, the use of the device for boiler water level control and alarm is completely feasible. However, after years of actual use, it was found that this device would sometimes fail during operation, so we did some investigation and analysis to find out the cause of its failure. After improvement, we have designed and manufactured several DSK boiler water level monitors, added integrated pressure regulator module, improved integrated signal processing circuit, and achieved good results.