In order to quantitatively analyze the sensitivity of early-warning aircraft based cooperative midcourse-guidance accuracy to errors, the acquisition probability under cooperative midcourse-guidance is modeled.Firstly, the feasibility of cooperative midcourse guidance scheme based on early warning aircraft is analyzed.Secondly, the calculation process of midcourse guidance command is analyzed according to the guidance scheme, and the model for midcourse-guidance command calculation is established.Then, five error sources affecting cooperative midcourse guidance are analyzed, and each error is modeled, which is then added to the midcourse-guidance command calculation model.Monte Carlo method is used to calculate the acquisition probability of cooperative midcourse guidance.Finally, based on Monte Carlo model, the sensitivity of acquisition probability of cooperative midcourse guidance to errors is analyzed by orthogonal experiment method.According to variance analysis results and the differences between guidance performance of early warning aircraft and fighter aircraft, it is concluded that the urgent task of realizing early-warning aircraft based midcourse guidance is to improve the radar search cycle and the height measurement accuracy of the early warning aircraft.