Abstract: Due to various reasons such as production, use, and maintenance, there is a high probability that substation batteries will experience open circuit faults during operation. This not only seriously affects the normal operation of the substation, but also poses a potential threat to the safety and stability of the power grid. Therefore, a substation battery open circuit intelligent warning method based on the improved Canny operator is proposed. Firstly, using the improved Canny operator for battery image preprocessing provides accurate data support for subsequent processing and analysis; secondly, perform internal resistance value detection and open circuit fault location of the battery; finally, the detection of internal resistance values and the location of open circuit faults result in intelligent warning of battery open circuits in substations. The experimental results show that the intelligent open circuit warning method for substation batteries based on the improved Canny operator can accurately predict the voltage of the battery pack when an open circuit fault occurs. As the resistance of the battery quickly drops below 2 V when an open circuit fault occurs, it proves that the voltage measurement results of this method are consistent with the fault warning situation, and the warning effect is better.