A high-efficacy, long-acting, slow-release formulation of the poorly soluble drug, comprising solid dispersion of the poorly soluble drug, silica nanoparticles loaded with the poorly soluble drug, matrix material, and release enhancer, wherein the mass ratio of these components is solid dispersion of the poorly soluble drug: silica nanoparticles loaded with the poorly soluble drug: matrix material: release enhancer=1: 0.5˜1.25: 0.1˜0.3: 0.1˜0.3; the said solid dispersion of the poorly soluble drug contains povidone K30, soybean lecithin, and acrylic resin IV, wherein the mass ratio of the drug and the accessory materials is poorly soluble drug: povidone K30: soybean lecithin: acrylic resin IV=1: 1-3: 0.3˜0.8: 0.2˜0.5. Compared with the existing formulations, the in vivo half life of the high-efficacy, long-acting formulation of the poorly soluble drug disclosed in this invention is 2.3˜14.8 times longer while the mean residence time (MRT) of which is 7.94˜4.52 times longer; when tested in vivo in Beagle dogs, this new formulation of the poorly soluble drug presents a smoother concentration-time curve and reaches a continuous release for 72 hours. This invention discloses its preparation method.