The invention discloses a water quality stabilizer achieving recycling of all industrial waste water and zero pollution discharge and a preparation method of the water quality stabilizer. The water quality stabilizer is prepared from an agent A, an agent B and an agent C. The agent A is prepared from, by mass, 20%-50% of antisludging agent, 15%-60% of dispersing agent, 10%-40% of chelating agent, 5%-10% of stabilizing agent, 0.2-1.2% of synergist, 5%-15% of bactericide and the balance water. The agent B is prepared from, by mass, 20%-50% of phytic acid, 15%-60% of zinc nitrate, 10%-40% of lanthanum nitrate, 5%-10% of nickel nitrate, 5%-10% of 2-hydroxyphosphonoacetic acid, 5%-10% of cobalt nitrate and the balance water. The agent C is prepared from, by mass, 30%-60% of piperazine hexahydrate, 30%-60% of aminoethyl piperazine hexahydrate and the balance water. By means of the water quality stabilizer, a circulating water system cannot scale or be corroded for many years, and zero emission of an industrial circulating water system is achieved.