The curved flow channel (1, 2) with a built-in lattice structure (11, 21) provided by the present application is configured with the lattice structure (11, 21) disposed at the outer inside wall of the curved section away from a center of curvature of the curved section. Through geometry and distribution design of the lattice structure (11, 21), flow rate and flow direction of fluid impacting the lattice structure (11, 21) can be altered, which achieves the purpose of flow rate redistribution in the curved flow channel (1, 2) and produces a downstream flow field with uniform distribution.