The invention belongs to the technical field of wireless communication, and relates to a design method of a receiver of a backscatter communication system based on MPSK carrier. The invention establishes a receiver design flow of an environment-based backscatter communication system from the perspective of channel estimation; converts a detection signal into a detection channel according to the principle that the corresponding channel is different under two assumptions of tag signals; and directly uses the estimated signal to make a decision. Therefore, the complexity of the receiver is reduced.