The invention discloses a monitoring strategy for leaking of a jetting device of a gas engine. The monitoring strategy comprises the steps of starting and stopping signal detecting by a fuel cut-off valve, engine state signal detecting, position detecting of a start key of an automobile, logical processing, setting of the pressure safety range of the jetting device, leaking judging of the jetting device and the like. The monitoring strategy has the beneficial effects that 1, original configurations of the engine and the structure of an original gas jetting device do not need to be changed; and 2, through an ECU, the sealing performance of a jetting rail and a nozzle is effectively judged by parameters detected by an existing state monitoring device, and failure prompting is conducted to the leaking problem. The monitoring strategy is used for judging the vehicle condition for a driver, more direct support is provided, accordingly the consistency of the engine state can be monitored, and worsening of power performance, economic performance and emission performance due to gas leaking is avoided.