The invention provides a method for preparing hexagonal mesh polythene warp-knitting net for a deep-water net box and a deep-water net bag, relating to the preparation of webbing for deep-water net box and net bag; the problem to be solved is to improve strength performance of the polythene warp-knitting net for deep-water net box and net bag, exchange performance of internal and external waters and fishing adaptability. The technical proposal comprises that high-density polyethylene is used as raw material to prepare the high-strength fishing polyethylene monofilament with the diameter of 0.20mm and hexagonal warp-knitting mesh shapes by a high-temperature high-time self-reinforced technique; the method is characterized in that weft-lining wreathing empirical coefficient of hexagonal mesh polyethylene warp-knitting net is 0.160-0.200; the wreathing number is equal to the product of strand number and wreathing empirical coefficient, the weft-lining empirical coefficient is 0.400-0.500, the weft-lining number is equal to the product of the strand number and the weft-lining empirical coefficient and the weft-lining number is an even number. The method is used for preparing hexagonalmesh polythene warp-knitting net for deep-water net box and net bag.