The invention belongs to the field of novel composite materials and particularly relates to a basalt fiber polypropylene composite material enhanced by expansion flame retardants and a method for preparing the same. The polypropylene composite material comprises, by weight, 48.5% to 78.5% of polypropylene, 0.3% to 2% of heat stabilizers, 0.2% to 1% of processing agents, 10% to 40% of flame retardant master batches, 1% to 5% of compatilizers and 10% to 35% of basalt fibers. Mechanical properties of the polypropylene composite material are improved, for example, bending strength, tensile strength and tensile modulus, and particularly the bending strength is improved by 39%, the excellent mechanical properties enable the polypropylene composite material can be used in certain special occasions, such as fields of aerospace, metallurgy and chemical industry, auto parts and the like. As expansion flame retardants are added, the flame retardant effect of the polypropylene composite material is good, and poisonous gas and smog cannot be emitted during combustion to pollute the environment.