The invention provides a preparation method of a porous PCL-TCP (polycaprolactone-tricalcium phosphate) artificial bone scaffold with a drug sustained release function. The PCL-TCP artificial bone scaffold prepared with the method has biological activity and regular pore diameter, the porosity is higher than or equal to 60%, the pore diameter is in a range of 300-500 mu m, the compressive strength is higher than or equal to 20 MPa, the compression modulus is 0.5-1 GPa, the degradation time of the PCL-TCP artificial bone scaffold is gradually prolonged from the edge layer to the middle layer, the degradation time of the middle layer of the scaffold is 1-3 years, the degradation time of the edge layer is 2-6 months, besides, composite printing with chitosan microspheres/collagen wires is performed, chitosan microspheres wrap a drug for promoting bone formation, and the sustained release function of the drug is played. The prepared PCL-TCP artificial bone scaffold has elasticity modulus and mechanical strength which are close to those of natural bone tissue, a porous structure and the chitosan microspheres in the porous structure can realize sustained release of the drug for promoting bone formation, new bone tissue is induced to grow, the problem about bone-material interface bonding is solved, a good osseointegration effect is realized, the PCL-TCP artificial bone scaffold has better mechanical compatibility and osseointegration capacity than a metal material, and the ideal material and preparation method are provided for overcoming poor bone healing of a patient with bone defects.