The paper analyses the characteristic of traffic flow on freeway. Then a freeway incident detection method based on observing the amplitude curve of wavelet coefficient is advanced, whose key model is fitted between flow and time-occupy ratio in the form of bifurcation equation in order to magnify the characteristic of singular point by wavelet transform, with an improved Newto-Core Numerical Integral Method concerning the characteristic of Marr wavelet function as its key. At the end of this paper, a series of traffic flow data surveyed on Guangzhou...