Method and device for detecting air leakage of air inlet pipe of engine

The invention provides a method and device for detecting air leakage of an air inlet pipe of an engine. The method comprises the steps of judging whether the air leakage detection condition of an air inlet pipeline in front of a throttle valve is met or not according to the system state quantity of the engine; the method comprises the following steps: acquiring a first flow difference factor, a second flow difference factor and a mixed gas closed-loop difference factor under the condition of meeting the condition of air leakage detection of an air inlet pipeline in front of a throttle valve, and judging whether air leakage is suspected based on the first flow difference factor, the second flow difference factor and the mixed gas closed-loop difference factor, and obtaining an air leakage detection result. The air leakage state of the air inlet pipeline in front of the throttle valve under different working conditions can be detected, air leakage or air leakage can be recognized, the phenomenon of unstable rot