In order to solve the problem of whole course tracking of ballistic missile in the early warning system of low earth orbit (LEO), and improve the scheduling efficiency of sensors, introduce a sensor scheduling method based on Analytic Hierarchy Process (AHP).This paper analyzed the visibility of the target and the sensor scheduling problem, summarizes the constraints of sensors in the low orbit early warning satellites, constructed real-time sensor scheduling model based on Analytic Hierarchy Process, and finally carried on the simulation analysis with the STK software. The simulation experiments show that, this model can effectively reduce sensor scheduling for the time and target handoff times and it has a good performance.