Abstract: By using the network theorem, the authors consider that one of both sensory channels in transient Rayleigh wave prospecting is taken as the input node of a network, the other as the output node. An universal signal model of both channels is provided, the substance of difference between the phase velocities and their dispersion curves calculated both by the transient source and stable source are interprated. The improved algorithm of the phase velocity of transient Rayleigh wave is provided. The result indicates that the corrected phase velocity is decreased obviously, and the resolution of its dispersion curve is somewhat increased.