The invention relates to the technical field of polypropylene material improvement, in particular to an environment-friendly, high-efficiency and flame-retardant polypropylene complex and a preparation method thereof. The complex comprises raw materials in parts by weight as follows: 35-74 parts of polypropylene, 15-30 parts of a halogen-free flame retardant, 1-2 parts of an antioxidant, 0.5-2 parts of a coupling agent and 0-2 parts of other assistants, wherein the halogen-free flame retardant is prepared from modified ammonium polyphosphate, nano carbon spheres and hydroxyapatite by mixing; the nano carbon spheres are prepared from glucose; modified ammonium polyphosphate is prepared from ammonium polyphosphate which is coated with methylsilane and has polymerization degree higher than 1700. By adding the halogen-free flame retardant to the polypropylene complex, good mechanical properties are kept while the complex is endowed with good flame retardance, besides, environmental pollution and harm to human bodies caused by the traditional flame-retardant halogenated polypropylene material are avoided, the polypropylene complex is non-toxic and environmentally friendly and has important actual application value, and the use quantity of the flame retardant is reduced greatly.