The invention discloses a non-oxidized type compound bactericide for water treatment and a preparation method thereof. The non-oxidized type compound bactericide is prepared by the steps of weighing glutaraldehyde, acrylic acid-2-acrylamide-2-methyl propane sulfonic acid copolymer, tetradecyl benzyl dimethyl ammonium chloride, etidronic acid, water, PBTCA, a polymerization inhibitor, sulfonic acid, polyol phosphonate ester, PESA, a dispersant, sodium tungstate, bitertanol, sodium benzoate and acrylic acid-hydroxy-propyl acrylate copolymer in parts by weight, and mixing uniformly. The product is 100% water-soluble, and has a sterilizing rate of 99.9-100% to escherichia coli, staphylococcus aureus, candida albicans, neisseria gonorrhoeae, penicillium notatum, aspergillus, saprophytic bacteria and salmonella; and the sterilizing rate is 98-100% after the bactericide is placed for one month at 50-60 DEG C, the sterilizing rate is 97.9-99.9% after the bactericide is placed for half a year at 40-50 DEG C, and the sterilizing rate is 97.5-99.5% after the bactericide is placed for 1-2 years at room temperature.