The invention discloses a three-dimensional microchannel and pulsating flow cooling device, which relates to the technical field of radiators, and specifically relates to a new three-dimensional microchannel radiator using pulsating or intermittent fluid to dissipate heat and its 3D printing manufacturing method. The heat dissipation device includes a radiator, a pulsating pump, a cooler, and a connecting pipe; the radiator is closely attached to the heat source, and the radiator, the pulsating pump, and the cooler are connected in series through the connecting pipe, and the radiator includes: a liquid injection port , the bottom heat dissipation structure, the middle layer heat dissipation structure, the top layer heat dissipation structure, and the liquid outlet. The bottom heat dissipation structure, the middle layer heat dissipation structure, and the top layer heat dissipation structure are stacked in sequence, which has a good heat dissipation effect and is produced as one by 3D printing. After installation, the heat dissipation effect is further improved.