The invention provides polypropylene compound powder for selective laser sintering, which is prepared from the following components in parts by weight: 100 parts of polypropylene-maleic anhydride grafted polypropylene, 0.1-1.0 part of carbon nano-tube, 0.3-1.0 part of flow additive and 0.1-1.0 part of antioxidant. The invention further provides a method for preparing the compound powder, which comprises the following steps: (1) dissolving the polypropylene powder and maleic anhydride grafted polypropylene powder in an organic solvent, heating under a stirring state to a target heating temperature, and continuously stirring at a constant temperature to form a polypropylene solution; (2) quenching the polypropylene solution to a target quenching temperature, standing at a constant temperature until precipitate is generated in the solution; (3) separating the precipitate, washing and drying to obtain the polypropylene-maleic anhydride grafted polypropylene powder; and (4) uniformly mixing and stirring the polypropylene-maleic anhydride grafted polypropylene powder with the carbon nano-tube, the flow additive and the antioxidant.