The invention relates to a flow-dividing annular micro-channel radiator, which is mainly composed of a circular micro-rib plate, a circular flow dividing structure and a cover plate. The special flowdividing structure of the radiator is formed by annular micro-channels on the micro-rib plate and flow dividing channels on the flow dividing structure. The diameter of the circular flow dividing structure is less than that of the circular micro-rib plate, and an annular channel formed by the circular flow dividing structure and the circular micro-rib plate serve as a primary flow dividing channel, thereby effectively solving a problem of uneven primary flow dividing caused by a stagnation effect of a cooling working medium at the tail end of the flow dividing channel. Secondary flow dividingchannels are of a gradually shrinking structure, which can also weaken the influences of fluid stagnation inside the flow dividing channel and increase the uniformity of flow distribution between overflowing channels. The flow-dividing annular micro-channel radiator further improves the problem of nonuniform flow distribution on the basis of reserving advantages of the micro-channel flow dividingstructure, and has high heat exchange capacity and heat exchange limit. The flow-dividing annular micro-channel radiator is compact in structure and good in heat exchange capacity, and has excellent application prospects in the aspect of cooling for high heating equipment such as electronic chips, lasers and rectifiers.