The invention discloses a polypropylene composite for automobile bumpers, and a preparation method thereof. The polypropylene composite for automobile bumpers comprises 60-80% of polypropylene resin, 10-20% of inorganic filler, 5-15% of thermoplastic elastomer, 5-10% of compatilizer, 0.1-1% of antioxidant, 0-1% of light stabilizer and 0-1% of processing aid. The preparation method of the polypropylene composite for the automobile bumpers comprises the following steps of: firstly, adding the polypropylene resin, the thermoplastic elastomer, the compatilizer and the inorganic filler into a high-speed mixing machine for uniformly mixing, then adding the antioxidant, the light stabilizer and a lubricant to continuously stir and mix at high speed, and finally adding the uniformly mixed material into a double-screw extruder for extruding and forming to obtain the polypropylene composite. Due to the addition of the compatilizer, compared with the prior art, the automobile bumpers made of the polypropylene composite provided by the invention have higher impact resistance and lower cost and can better meet the requirement of customers for an automobile bumper material with high cost performance.