The invention discloses a forming device and a forming method of a continuous fiber reinforced thermoplastic resin preimpregnation sheet material. The forming device comprises a creel, a fiber pre-dispersing device, a single-screw extruder, a screw-type smelting immersing mold, a secondary rolling device, a cooling traction machine and a coiling machine; 1 to 3 screw immersing rolls are arranged in the screw-type smelting immersing mold, a screw groove is formed in the outer surface of each screw immersing roll, and each screw immersing roll is driven by a motor to rotate in the screw-type smelting immersing mold. When the screw immersing rolls rotate, resin flows along the screw groove so as to immerse the fiber in the longitudinal direction, due to the extrusion effect, melt can flow along the direction perpendicular to the fiber, and the transverse immersion can be realized. The continuous fiber reinforced thermoplastic resin preimpregnation sheet material prepared by utilizing the forming device is good in impregnation effect, high in impregnation efficiency and good in production stability, so that a product excellent in performance can be obtained.