The invention discloses high surface hardness halogen-free flame retardant polypropylene. The high surface hardness halogen-free flame retardant polypropylene is prepared from the following raw materials in parts by weight: 70 to 100 parts of polypropylene, 10 to 20 parts of hardening agent, 5 to 10 parts of ethylene-octylene copolymer, 3 to 15 parts of microencapsulated red phosphorus, 5 to 15 parts of crystallization type II ammonium polyphosphate, 10 to 100 parts of inorganic flame retardant, 0.5 to 7 parts of isocyanate curing agent, 0.5 to 10 parts of coupling agent, 0.4 to 2 parts of antioxidant and 0.5 to 2 parts of calcium stearate, wherein the hardening agent is aluminum potassium sulfate and the isocyanate curing agent is Bayer Desmodur E1361 BA. The invention also provides a preparation method of the high surface hardness halogen-free flame retardant polypropylene. The high surface hardness halogen-free flame retardant polypropylene prepared by the preparation method provided by the invention has the advantages of high surface hardness, excellent mechanical properties and good flame-retardant performance; in addition, the UL94 flame retardant rating of the high surface hardness halogen-free flame retardant polypropylene reaches V0 grade.