A method for photosynthesis reaction of algae microbe, comprising: (a) providing a photosynthesis reaction unit, comprising a transparent piping, a communicating unit, a collecting valve, a pressured liquid transport unit with a transport pipe, an oxygen jet device with a liquid inlet, and a connecting pipe; (b) injecting an algae and microbe nutrient solution into the transparent piping, circulating the nutrient solution within the transparent piping for photosynthesis to generate oxygen, wherein the nutrient solution flows to the communicating unit, the collecting valve, and the pressured liquid transport unit; (c) determining an included angle on a horizontal cross-sectional surface of the oxygen jet device between an axial line of the transport pipe and a normal line passing through a central point of the oxygen jet device, wherein the included angle is adjustable according to different kinds of algae; (d) opening the pressured liquid transport unit to force the nutrient solution to flow toward the oxygen jet device from the transport pipe, wherein the nutrient solution flows into the oxygen jet device from the transport pipe via the liquid inlet along the included angle and caused a shear force on the algae, and is splashed into the oxygen jet device to form a spinning splash by which the oxygen is ventilated, wherein the shear force is reduced when the included angle is smaller; (e) collecting the nutrient solution in the oxygen jet device and the connecting pipe; (f) flowing the nutrient solution into the transparent piping for further photosynthesis; and (g) taking the nutrient solution from the collecting valve. (a) providing a photosynthesis reaction unit, comprising a transparent piping, a communicating unit, a collecting valve, a pressured liquid transport unit with a transport pipe, an oxygen jet device with a liquid inlet, and a connecting pipe; (b) injecting an algae and microbe nutrient solution into the transparent piping, circulating the nutrient solution within the transparent piping for photosynthesis to generate oxygen, wherein the nutrient solution flows to the communicating unit, the collecting valve, and the pressured liquid transport unit; (c) determining an included angle on a horizontal cross-sectional surface of the oxygen jet device between an axial line of the transport pipe and a normal line passing through a central point of the oxygen jet device, wherein the included angle is adjustable according to different kinds of algae; (d) opening the pressured liquid transport unit to force the nutrient solution to flow toward the oxygen jet device from the transport pipe, wherein the nutrient solution flows into the oxygen jet device from the transport pipe via the liquid inlet along the included angle and caused a shear force on the algae, and is splashed into the oxygen jet device to form a spinning splash by which the oxygen is ventilated, wherein the shear force is reduced when the included angle is smaller; (e) collecting the nutrient solution in the oxygen jet device and the connecting pipe; (f) flowing the nutrient solution into the transparent piping for further photosynthesis; and (g) taking the nutrient solution from the collecting valve.