The invention belongs to the technical field of waste tire pyrolysis, and mainly discloses a waste tire pyrolyzing and cracking tube cracking system based on heat accumulating type radiant tube heating to prepare clean combustible gas. To solve the deficiencies in the prior art, the waste tire pyrolyzing and cracking reaction system is designed and developed. The reaction system can be used for conducting pyrolyzing and cracking operations, oil gas generated in the pyrolyzing chamber can enter a cracking tube in a cracking chamber for deep cracking, oil gas can stay in the cracking tube for a long time, macromolecular tar molecules are cracked into micromolecular gaseous hydrocarbon, and the reactor can generate plenty of cracked gas, so that the problem that the produced pyrolytic tar is hard to utilize is solved, and clean and efficient utilization of the waste tire can be really realized.