The invention belongs to the technical field of gear detection devices, and relates to a gear integrated runout inspection instrument comprising a pedestal. A guide rail is installed on the pedestal. A first slide base and a second slide base are slidably arranged on the guide rail. The position, which is close to one side of the second slide base, of the pedestal is provided with a supporting base. A dial indicator is installed on the supporting base. The side rod of the dial indicator is connected with a connecting rod stretching out of the second slide base. A compression spring is arranged between the supporting base and the second slide base. The two ends of the compression spring are respectively abutted against the supporting base and the second slide base. The top surface of the second slide base is provided with a floating spindle used for fixing an inspected gear. The top surface of the first slide base is provided with a fixing spindle used for fixing a standard gear. The first slide base is also provided with a locking screw used for limiting and fixing the first slide base. According to the device, the integrated runout of the gear can be conveniently detected and the damaged tooth surface can be accurately searched.