In view of complex change of chaff corridor distribution and the fact that jamming effect cannot be quantified， method for simulating the process of radar target detection in the context of foil corridors is proposed. The attenuation effect model， diffusion model and radar beam thickness model of foil corridor are established and implemented by Matlab. By setting up a variety of scenarios for simulation， the general rules of foil corridor in terms of length， width and selection of flight parameters of the attacking aircraft are summarised， which can quantitatively assess the jamming effect and optimise the application strategy of foil corridor jamming.