The invention discloses a method for preparing a carbon fiber reinforced thermoplastic composite material, which comprises the following steps: 1)alternatively paving carbon fiber and thermoplastic resin in a die, wherein a bottom layer and a top layer of the die are thermoplastic resin, closing the die and applying pressure; 2)accessing power supply to a carbon fiber layer, rapidly heating under current effect, when the temperature is higher than the melting point of thermoplastic resin, fusing thermoplastic resin, dipping carbon fiber under pressure; and 3)breaking power, cooling the die, and then opening the die to obtain the carbon fiber reinforced thermoplastic composite material. The method takes carbon fiber as a heat-generating body, the electrothermal conversion efficiency can reach as high as more than 90%, and the energy saving effect is obvious; simultaneously, carbon fiber is capable of melting thermoplastic resin and completing dipping, and has the advantages of short moulding time and good dipping effect, formation of good cross section of thermoplastic resin and fiber can be realized, composite material performance is increased, and processing of product with large thickness can be realized in short time.