The invention discloses an external preparation of a series of neurokinin-1 receptors (NK1 receptors) inhibitors and a preparation method of the external preparation. The NK1 receptor inhibitors comprise, but are not limited to, aprepitant, fosaprepitant, rolapitant, netupitant or pharmaceutically acceptable salts thereof. The external preparation comprises, but is not limited to, ointment, cream, gel, tincture, lotion, aerosol, spray, liniment, a foaming agent, patch, emplastrum and the like. The external preparation of the NK1 receptor inhibitors can slowly deliver the medicine at a constant speed, and reduce the blood concentration fluctuation caused by dissolution and absorption of the oral medicine; the pertinence to local lesions can be improved, and the side effects of the whole body are reduced; and meanwhile, a choice with high compliance is provided for patients inconvenient to take orally, and the external preparation has important significance in relieving the pain of cancer patients clinically.