In order to obtain the distribution rules of fluctuation pressure of train head surface, body-fitted quadrilateral and hexahedron grid was obtained of high speed train head surface based on parameter space mapping approach. The fluctuation pressure caused by streamlined curved surface of train head was calculated with LES (large eddy simulation), the distribution rules of fluctuation pressure were obtained: the fluctuation pressure is local, namely the fluctuation pressure produced at a certain point mainly affects this point, and the influence on other point weakens promptly when it is apart from this point; The frequency band of fluctuation pressure is very wide, and does not have obvious main frequency. The amplitude of fluctuation pressure is greater at low frequency. With the increase of frequency, amplitude drops continuously according to negative index law. The major energy of 1/3 octave band fluctuation pressure focuses on the frequency scope from 20 Hz to 500 Hz. With the increase of train speed, the major energy of frequency spectra has the tendency that moves to high frequency.
