Abstract: By applying generalized likelihood ratio test (GLRT), This paper gives the detector of polynomial phase signal (PPS) with unknown parameters. The detector is optimal in Neyman-Pearson sense. When the power of phase polynomial is one or two respectively, periodogram and chirp Fourier transform method are the corresponding optimal detection methods. The probability density function, detection probability, and false detection probability are derived. Consequently the relationship between detection probability and false detection probability, signal energy to noise ratio, and the number of searching points in the parameter space are achieved. The simulation demonstrates the validness of the analysis.