A method for separating the overlap signals is proposed in this paper.It sets up a multi-signals separating model using the polynomial phase fitting to estimate the signal phase.This method changes multi-signals separation into the sequence and channel parameters estimation.Then,the method for joint estimating the sequence and channel parameters is took to estimate the each signal amplitude and phase of multi-signals and separate the multi-signals.The method can separate signals entirely overlapped in time and frequency using single channel reception.Simulation and the practical experiment results indicate that the method has the excellent performance.