Method for detecting short circuit fault of spark plug of engine

The invention discloses a detection method for a spark plug short circuit fault of an engine, and relates to the technical field of engine fault detection. The method for detecting the short-circuit fault of the spark plug of the engine comprises the following steps that the discharge duration T1 of an ignition coil under the first working condition is obtained, and the first working condition is that the engine operates at the low load and the low rotating speed; and the discharging duration T2 of the ignition coil under the second working condition is obtained, and the second working condition is that the engine operates under the high load and the high rotating speed. And calculating a difference value between the discharge duration T1 under the first working condition and the discharge duration T2 under the second working condition. Judging whether the difference value is smaller than a preset difference value; and if yes, judging that the engine has a spark plug short-circuit fault. According to the dete