The invention relates to a purifying and separating method of high-salt waste water and nanofiltration equipment thereof and belongs to the technical field of waste water purifying treatment. In order to solve the problem of easy scaling in the prior art, the invention provides the purifying and separating method of high-salt waste water and nanofiltration equipment thereof. The nanofiltration equipment comprises a housing with an inner cavity. A nanofiltration membrane is arranged in the housing, a water inlet I and a water outlet II are formed in the housing, and the water inlet I communicates with a high-salt waste water side; the water outlet II communicates with a purified water side; a water outlet I communicating with the high-salt waste water is also formed in the housing; and a water inlet II communicating with the purified water side is formed in the housing. The method comprises the following steps of: conveying the high-salt waste water through a water pump I and conveying the purified water through a water pump II to the nanofiltration equipment, wherein the high-salt waste water and the purified water flows through two sides of a nanofiltration membrane to be nano-filtrated; and performing separation as the pressure of the high-salt waste water side is greater than that of the purified water side. The method provided by the invention can effectively solve the problem of corrosion influence and scale prevention in the presence of a monoacid salt in the high-salt waste water.