The invention discloses a backflow type sewage treatment reactor based on a catalytic reaction mechanism, and relates to the technical field of sewage treatment. The backflow type sewage treatment reactor comprises a base, wherein a reaction tank is fixed on the upper surface of the base, a rotary catalysis device rotationally matched with the reaction tank is arranged in the reaction tank, the outer portion of the reaction tank is communicated and connected with a backflow warmer sleeved on the reaction tank, a backflow pipe connected with the rotary catalysis device is fixed at the upper end portion of the backflow warmer, two heat transfer assemblies are symmetrically arranged on the upper surface of the base, the backflow warmer is in clearance fit with the heat transfer assemblies, and two heat supply devices are symmetrically arranged on the upper surface of the base and attached to the heat transfer assemblies. According to the present invention, with the design of the backflow warmer, the backflow pipe, the supercharger, the backflow assembly, the heat transfer assembly and the heat supply device, the heating of the sewage in the backflow warmer can be achieved, and the backflow type heating of the sewage in the reaction tank is achieved through the loop formed by the reaction tank, the backflow warmer, the backflow pipe and the backflow assembly, so that the sewage heating uniformity is substantially improved.