The invention provides a CPVC pipe for fire protection engineering and a preparation method of the CPVC pipe. The CPVC pipe comprises a CPVC base pipe, an epoxy powder layer, an adhesive layer, a flame-retardant layer, a heat-resistant layer, an antioxidant layer, an antistatic layer, an anticorrosive layer and a protecting glue layer and a liner layer, wherein the epoxy powder layer, the adhesivelayer, the flame-retardant layer, the heat-resistant layer, the antioxidant layer, the antistatic layer, the anticorrosive layer and the protecting glue layer are sequentially arranged on the outer wall of the CPVC base pipe from inside to outside; the liner layer is arranged on the inner wall of the CPVC pipe; and the flame-retardant layer contains the following components in parts by weight: 30-40 parts of polyurethane resin, 25-35 parts of methyl methacrylate, 10-15 parts of butyl acrylate, 10-15 parts of acrylamide, 10-15 parts of polyvinyl alcohol, 10-15 parts of ammonium polyphosphate,15-25 parts of cellulose acetate, 1-5 parts of a defoaming agent, 1-5 parts of a silane coupling agent and 60-70 parts of deionized water. The CPVC pipe has excellent flame retardance, limited flame spreading property or low smoking performance, high corrosion resistance, good mechanical strength and excellent weather resistance and wear resistance.