The quasi-neutral plasma layer around a hypersonic vehicle interferes with communication electromagnetic (EM) signals. Conventional communication methods cannot adapt to this special channel environment, and the communication link is always interrupted. The simulation of hypersonic plasma channels supports the study of adaptive communication methods, and the time consumption determines the efficiency of communication method evaluation. To reduce the time consumption of channel simulation, this article establishes the mapping relationship between the electron density distribution and the hypersonic plasma channel envelope and phase based on the EM wave propagation mechanism in plasma. The channel envelope and phase sequences can be directly obtained from the electron density change sequence, avoiding the time consumption caused by many numerical operations. The simulation results show that the proposed efficient simulation method is hundreds of times shorter than the EM calculation method under the same conditions and that the simulation error is less than 0.5% in most cases, which indicates that the proposed method can guarantee accuracy, greatly reduce the hypersonic plasma channel simulation time, and provide an efficient and accurate channel environment to support research on adaptive communication methods for hypersonic vehicles.