Health diagnosis method and system for propulsion system with multi-machine parallel orbit control engine

The invention provides a health diagnosis method and system for a propulsion system with a multi-parallel orbit-control engine, and the method comprises the steps: carrying out the sequential pre-work of the orbit-control engine before the orbit-control engine works officially, and enabling the pre-work time to be not less than 30 ms; whether the self-locking valve is normally opened or not is judged by arranging a pressure sensor on the downstream of the storage tank to monitor whether water hammer pressure is generated or not when an engine works. A temperature sensor is arranged on each orbit control engine, and if the temperature sensor monitors that the temperature rises, it is indicated that the corresponding orbit control engine works normally. Based on the two methods, the states of the self-locking valve and the engine of the propulsion system can be judged before the spacecraft officially implements the orbit control action, risks are recognized and eliminated in advance, irreversible disastrous con