The invention discloses a differential-speed conical twin-screw extruder mainly consisting of a machine head, a heating and cooling device, a machine barrel, an air outlet, two screws, a feeder, a driving device and a motor. The two screws are conical screws, have different numbers of screw flights and are divided into a female rotor and a male rotor, and the ratio of revolutions of the female rotor to the male rotor is in inverse proportion to the ratio of the numbers of the screw flights of the female rotor to the male rotor; the screws are at least provided with a thread meshing region during combination, the number of the screw flights of the female rotor is integral multiple of that of the male rotor in the thread meshing region, and the ratio of the rotation speeds of the female rotor to the male rotor is in inverse proportion to the ratio of the numbers of the screw flights of the female rotor to the male rotor, thus differential-speed rotation can be realized, and the female rotor and the male rotor are not influenced during motion. According to material processing requirements, thread sections with different leads and section molded lines or other forms can be arranged on different sections, such as a feeding section, a fusing section, an exhaust section and a measuring section of each screw, and the screws can be meshed and can not be meshed in different sections during mounting, besides at least one thread meshing region rotated in differential speeds is ensured, thus a function of reinforcing mixing or other functions can be realized. The extruder disclosed by the invention has excellent mixing, plasticizing and conveying capabilities and is suitable for machine-shaping of various granular materials, powder materials, even block materials, such as plastics, rubber, foods, explosives and the like.