Groove milling device of hollow wood-plastic plate production line

The utility model discloses a groove milling device of a hollow wood-plastic plate production line, which comprises a fifth rack, a support roller is arranged at the upper end of the fifth rack, groove milling machines are arranged on two sides of the fifth rack, the groove milling machines are used for milling male and female grooves on two sides of a wood-plastic plate, and a groove milling mounting frame and a groove milling cutter are arranged in each groove milling machine. The groove milling cutter is mounted at the upper end of the groove milling mounting frame through a bearing, a sixth driving motor is arranged at the lower end of the groove milling mounting frame and is in driving connection with the groove milling cutter, and a pressing plate mechanism is arranged at the end, close to the fifth rack, of the groove milling machine and comprises a first fixed seat, a first movable seat and a third air cylinder; the first fixed seat is installed on the slot milling machine, the third air cylinder is i