Take the signal disturbing about GPS in transmitting into account , we have done some research on the scene of failure of LAAS by Simulation, which provided the failure data for integrity monitor system of LAAS. We designed several type of failures, including pseudorange failure, carrier phase failure, ionosphere failure and clock failure, and also gave models about all the failures. We can simulate the scene of failure by selecting the specified receiver, the specified satellite and the specified times.