Abstract: In order to study the optical characteristics of gas explosion at different ignition energy and accumulate empirical data about explosion suppression of gas explosion,in this study, starting from gas explosion ignition energy,we build a stable and reliable experiment system of variable ignition to use the weak and strong ignition energy to detonate gas and analyze the captured photos of high speed photography by MATLAB software.We can finally get three-dimensional optical characteristics laws of gas explosion under different ignition energy at the initial stage.There are three stages in the initial stage of gas explosion under the action of strong and weak ignition energy;the weakness fire of gas explosion has the slow reaction stage,the rapid increase stage and the stable development stage.The strong fire has a rapid increase phase about the reaction rate of gas explosion,the rapid increase stage and the stable development stage.