A method for remanufacturing a composite resin having high tensile strength and high rigidity into a remanufactured molded product having the same tensile strength and rigidity which includes the steps of: providing a molded product of a composite resin of thermoplastic resin and liquid crystal polymer having a crystal transition point higher than a minimum moldable temperature of the thermoplastic resin; crushing the composite resin into particles or pieces; heating the particles or pieces at a temperature higher than the transition temperature of the liquid crystal polymer to obtain a molten composite resin by using an injection forming apparatus; extruding the molten composite resin at a temperature higher than the transition temperature of the liquid crystal polymer to obtain a moldable composite material of a sheet or strand form; and forming the moldable composite material into a molded product in a given shape at a temperature lower than the transition temperature of the liquid crystal polymer.