The invention provides a multi-clamping-point type semi-automatic rounding device for log rounding machining, and belongs to the technical field of log machining. The device comprises a device shell,vertical sliding grooves, grinding rollers, inclined sliding grooves, second grinding rollers, hydraulic rods, gears, an electric motor, a guide-out plate, a slag outlet hole, a lifting support, a conveying belt, arc inverted hooks, a glass cover, an auxiliary grinding pile, a steel bar, a second hydraulic rod, a guide wheel, a telescopic support, an infrared generator and an infrared receiver. The vertical sliding grooves are embedded in the front and back surfaces of the right side of the device shell, the grinding rollers are rotatably connected into the vertical sliding grooves through bearings, the inclined sliding grooves are embedded on the front and back surfaces of the right side of the device shell, and are located on the right sides of the vertical sliding grooves, the second grinding rollers are rotatably connected to the inner side surfaces of the inclined sliding grooves through bearings, the hydraulic rods are fixedly connected to the outer side surfaces of the verticalsliding grooves and the inclined sliding grooves, and are located on the front and back sides of the device shell, and the gears are fixedly connected to the outer side surfaces of one sides of the second grinding rollers.