Aiming at the difficulty of fault simulation in virtual maintenance training of a certain type of long-range rocket launcher weapon system, on the basis of studying the mechanism of fault generation, a fault model composed of maintenance object, fault source, fault phenomenon, fault propagation directed graph and detection point is established by using object-oriented method, and the simulation and operation of fault characteristic signal and fault phenomenon in virtual environment are studied. The typical fault modeling and simulation of certian type long-range rocket launcher fire control system is realized by Virtools. The reuslts show that the model can realize fault phenomena and data in real-time.