The invention provides purified water preparation equipment which comprises an outer tank; an ozone generator is fixedly installed on one side of the outer tank; a gas outlet pipe is fixedly connectedto a gas outlet on one side of the ozone generator; a connection pipeline is fixedly connected to one end of the gas outlet pipe through a flange; a conical pipe is fixedly connected to one end of the connection pipeline; screw rods are welded to the two sides of the outer surface of the outer tank respectively; a torsional spring is sleeved with the outer surface of each screw rod; one side of each torsional spring is provided with a bushing; a connection rod is welded to the top of each bushing; a threaded sleeve is in threaded connection to the outer ring of each screw rod; a sealing cushion plate is arranged on the top of the outer tank; the top of the sealing cushion plate is provided with a sealing plate; connection pieces are welded to the two sides of the top of the sealing platerespectively; one end of each connection piece extends into the corresponding connection piece; and the back side of the outer tank is fixedly provided with an ultrasonic generator. For the purified water preparation equipment provided by the invention, by arranging the ultrasonic generator, sound waves can be generated to remove scales on the inner wall of the outer tank, and the quality of purified water production is improved.