A porous bionic internal fixation device for promoting healing of a fractured bone includes a lag screw in a round rod shape, the lag screw is provided with fixation structures at both ends thereof, and on a body of the lag screw, a plurality of apertures directing laterally or obliquely are provided, and densely distributed micro-holes are provided on the body of the lag screw between the adjacent apertures. When in use, the both ends of the lag screw are respectively located in the bone at opposite sides of the fractured bone, so that the longitudinal direction of the apertures is aligned with the direction of the tensile trabeculae or the compressive trabeculae at the fractured bone, and the position of the apertures corresponds to the fractured bone.
