The invention provides a water pipe used in pipeline engineering and a preparation method thereof, and relates to the technical field of plastic pipes. The water pipe used in pipeline engineering includes the following raw materials in parts by weight: SG-3 type PVC resin, aluminum borate whiskers, acetyl Calcium acetone, 1,2‑polybutadiene, talc, silica gel, polysulfone resin, polyamide resin, polyurethane rubber, phenolic resin, graphite powder, ceramic fiber, nano silicon carbide, 2,6‑di tert-butyl-p-cresol, flame retardant, plasticizer, compatibilizer, heat stabilizer, light stabilizer and curing agent; the preparation method comprises the following steps: (1) weighing raw materials, (2) mixing, (3) ) Melt molding, cooling and shaping. The invention solves the deficiencies of the existing water pipes in flame retardancy, heat resistance and strength.