The utility model discloses a stress relief device for a groove-shaped rail seamless track of a tramcar. The rail car comprises a rail car framework and a rail clamping device, pulleys are rotatably connected to the surface of the rail car framework, a door-shaped base plate is installed at one end of the rail clamping device, a first inclined iron is installed at the bottom of the rail clamping device, a second inclined iron is installed in the rail clamping device, and a third inclined iron is further installed in the rail clamping device. The rail bumping vehicle framework is reasonable instructure; rollover can be prevented; the balance weight is proper; matched fixed roller with reasonable size, the sliding on the groove-shaped rail is stable; three pieces of special-shaped inclinediron are arranged on the rail clamping device; convenient assembly, the stress relief device is simple in structure, reasonable in design, high in efficiency and good in effect, is used for stress relief of the groove-type rail seamless track of the tramcar, has wide popularization and application value in tramcar rail transit construction, and solves the problems that existing stress relief equipment for the groove-type rail seamless track of the tramcar is complex in structure and poor in stress relief quality.