In the paper, the experiment results of time-serial interferograms of explosive flow field and initial combustion process are presented which are produced by using pulsed YAG laser to detonate initiating agent and obtained with timeserial interferometry. On this basis, a method of fringes curve detecting and the function of double cubic many-knot interpolating splines are used to extract the wave-front of shock wave. With the algorithm of serial wave-front registering the propagation velocity of shock wave is calculated quantitatively. At the same time, the distribution of temperature with the change of time in the process of initiating agent combustion is calculated quantitatively also.