A preparing method of a polyadipic acid butanediol ester-terminal hydroxyl multiwalled carbon nanotube composite film comprises the steps: (1) weighing 0.5g of PBA, placing in a volumetric flask, dividing into two parts, and adding good solvent chloroform of PBA respectively to fully dissolve the PBA; (2) weighing MWCNTs-OH subjected to vacuum drying treatment, placing in two bottles and determining the volume with chloroform to obtain MWCNTs-OH trichloromethane turbid liquid; (3) blending the PBA solution with the MWCNTs-OH solution to prepare the PBA/MWCNTs-OH blended film casting liquid; (4) preparing the PBA/MWCNTs-OH blended film casting liquid into a composite film at normal temperature, standing and melting the PBA/MWCNTs-OH composite film to remove a thermal history, annealing and crystallizing for culture to obtain the PBA/MWCNTs-OH composite film material. The process method is simple, can be applied to industrial production and has broad application prospect.