Method for generating wireless key using satellite channel

The present invention provides a method for generating a wireless key using a satellite channel. The method includes the steps that a satellite A sends a public pilot frequency sequence to a legal user B; the legal user B estimates a downlink legal channel by using the received public pilot frequency sequence, and pre-codes a local private pilot frequency sequence according to the information of the downlink legal channel, and sends the private pilot frequency sequence to the satellite A; the satellite A forwards the received private pilot frequency sequence to the legal user B; the legal userB uses the received private pilot frequency sequence and the local private pilot frequency sequence to estimate the uplink legal channel, transmits a random sequence to the satellite A, and combineswith the information of the uplink legal channel to obtain a shared random source; the satellite A uses the received random sequence as a shared random source; two parties of the legal communication perform key extraction acco