Longley-Rice channel model modifies the atmospheric refraction by the equivalent earth radius method,which is simple calculation but is not accurate.As it only uses the horizontal difference,but does not make use of the vertical section information,it does not agree with the actual propagation path.The atmospheric refraction error correction method of the Longley-Rice channel model has been improved.The improved method makes use of the vertical section information sufficiently and maps the distance between the receiver and transmitter to the radio wave propagation distance.It can exactly reflect the infection of propagation distance for the radio wave propagation loss.It is predicted to be more close to the experimental results by simulation in comparison with the measured data.The effectiveness of improved methods is proved by simulation.