A thermal dissociation colliding combustion technology characterized by that, extracting flame directly from the colliding combustion chamber of the combustor in a mechanical way, making it enter thethermal dissociation fuel chamber instead of decomposing the fuel in the decomposition combining heat reaction zone, then warming-up the burning-rate accelerator beyond the decomposition combining heat reaction zone through the flame jet flow tube, colliding the preheated burning-rate accelerator for inflammation under the action of the powerful jet of the heat decomposition jet. The advantages of the invention are the prevention of the polluted material of nitrogen oxide, reduced equipment investment, integrated operation cost and the maintenance expense.