The invention discloses a low-resistance three-way component based on an arc flow deflector. The low-resistance three-way component comprises a straight pipe and a branch pipe arranged on one side ofthe straight pipe and communicating with the straight pipe, and the branch pipe is divided from the straight pipe from the position where the branch pipe is located. The low-resistance three-way component is characterized in that the three-way component further comprises the flow deflector, the flow deflector is an arc-shaped plate, the radian of the flow deflector is the same with that of the outer wall of the branch pipe, the flow deflector is arranged in the branch pipe, and the bending direction of the flow deflector is coincident with that of the branch pipe. According to the low-resistance three-way component based on the arc flow deflector, the flow deflector is installed in the branch pipe of a traditional three-way component, the flow deflector is an arc-shaped plate, the radian of the flow deflector is the same with that of the outer wall of the branch pipe, and the bending direction of the flow deflector is coincident with that of the branch pipe. By arranging the flow deflector, on the one hand, energy dissipation of the downstream of the flow deflector can be effectively reduced, and on the other hand, fluid deformation generated by local components can be divided, sothat fluid resistance is reduced.