Early warning system and method for state monitoring and fault monitoring of marine main engine

The invention discloses an early warning system and an early warning method for state monitoring and fault monitoring of a marine main engine. The system comprises a sensor, signal noise reduction equipment, a data acquisition device, a central processing unit (CPU), a discriminator and an emergency actuator, wherein the signal noise reduction equipment is connected with the marine main engine and the data acquisition device; the data acquisition device is connected with the CPU through the discriminator; the CPU is connected with the emergency actuator; the emergency actuator is connected with the marine main engine and an acoustic-optical warning system; and the CPU comprises a fault detection processing unit and a display. Information entropy is taken as a weight determination tool of an equipment safety index, so that the objectivity of an index weight is reflected; a fault hidden danger index can be effectively determined, the system is timely maintained, and major accidents are prevented; and the index weight is determined by the information entropy, and an entropy weight is a dynamic weight, so the state of each index can be reflected in real time, and the index weight has timeliness.