The invention, belonging to the technical field of universal plastics modification, discloses a polypropylene composition and a preparation method thereof. The polypropylene composition disclosed herein comprises the following ingredients: 38.5-95 weight parts of polypropylene, 5-25 weight parts of toughening agent, 0-35 weight parts of inorganic filler, 0-0.5 weight parts of lubricant, 0-0.5 weight parts of light stabilizer, and 0-0.5 weight parts of antioxidant. The preparation method disclosed herein comprises the following steps: adding 38.5-95 weight parts of polypropylene, 5-25 weight parts of toughening agent, 0-35 weight parts of pretreated inorganic filler, 0-0.5 weight parts of lubricant, 0-0.5 weight parts of light stabilizer, and 0-0.5 weight parts of antioxidant in a high mixing machine to mix for 5-10 min; adding the mixture in a double-screw extruder from the charging hole, and granulating. According to the invention, under the condition of keeping excellent comprehensive performances, the polypropylene composition disclosed herein has low production cost, high cost performance, and strong competitive power on the market, and can be widely applied in the material fields of auto-inner ornaments, door sheets, bumpers, liners and shells of household appliances, etc.