The invention provides a long-fiber reinforce thermoplastic direct (LFT-D) forming method for a molded long whisker/glass fiber reinforced thermoplastic composite. The forming method comprises the following steps: mixing calcium sulfate whisker and polypropylene (PP) according to a mass ratio of (7-15%) to (95-85%), adding 3-5% of industrial white oil and mixing by virtue of a high-speed mixer; melting and plasticizing the mixed materials by virtue of a first-order screw extruder, adding modified glass fiber together with the mixed materials melted and plasticized by the first-order screw extruder to a second-order screw extruder according to mass ratio of 3 to 7, melting, mixing and extruding; and conveying the mixed materials extruded from the second-order screw extruder into a mould pressing die, clamping the die and maintaining pressure so as to obtain a finished product. By adding the long whisker to the glass fiber/thermoplastic composite as the third element, the forming method disclosed by the invention can be used for improving the strength and modulus thereof and can be used for reducing production cost.