Abstract: The paper used point-plate discharging model to simulate roof air flashover, verified feasibility of using two factors of pulses and power current to monitor occurrence of roof air flashover by analyzing experimental data, and obtained change range of two factors. It designed fuzzy controller to monitor occurrence of flashover taking pulses and power current as input variables and verified the controller by use of collected data of laboratory.The experimental result showed that the controller can observed air discharge state at any time, and using the controller to monitor roof air flashover is feasible.