The present invention discloses an X-type cross section radiator. The X-type cross section radiator comprise a strip base plate and a first-grade fin arranged on the strip base plate along the axial direction, the cross section, perpendicular to the axial direction, of the strip base plate is rectangular, the first-grade fin is arranged along the diagonal direction of the rectangular, the first-grade fin is provided with a second-grade fin, and the end portion of the first-grade fin is provided with a connection structure. The X-type cross section radiator is simple and reasonable in structure and enhanced in heat radiation area of a radiator with the same size through improvement of the position and the shape of the fin so as to improve the heat radiation efficiency, reduce the material utilization amount and decrease the production cost.