The invention belongs to the technical field of advanced composite material die-pressing molding, and provides a glass fibre composite material molding die. The glass fibre composite material molding die comprises an upper die body (1), a middle die body and a lower die body (3). The middle die body comprises a middle die frame (2), a first shape mosaic block (6), a second shape mosaic block (7), a mold core (4) and a block-shaped core die (5). The mold core (4) and the block-shaped core die (5) are installed at a boss through hole and a sunken groove of the lower die body correspondingly. The side face of a boss of the lower die body is provided with the first shape mosaic block (6) and the second shape mosaic block (7), the first shape mosaic block (6) is in surface connection with the second shape mosaic block (7), and the periphery is limited by the middle die frame (2). The upper die body (1) is installed on the middle die body, the upper die body and the middle die frame are connected and limited through positioning pins, and the middle die frame and the lower die body are also connected and limited through positioning pins.