In order to reduce the maintenance cost of fire control equipment, enhance the completeness of fire control system and improve the management efficiency, a state evaluation method based on rough set fusion and grey correlation analysis is proposed. Taking the ADA module in certain type tank fire control system as the research object, according to the redundancy and complexity characteristics of the signal of the fire control computer, the attribute reduction is carried out by using the rough set theory. Then the reduced signals are taken as the evaluation index, the state evaluation of the system is carried out by using the grey correlation analysis method, and the comparative analysis is carried out through the example at last. The results show that the algorithm has the advantages of simple calculation process and less space complexity, and can effectively evaluate the current state of fire control computer and sensor subsystem.