A permanent magnet canned motor pump comprising a pump casing, a triangle front support, an impeller, a containment shell, a stationary shaft and a canned motor, wherein the pump casing has a flow channel, adapted for containing the impeller, an inlet, an outlet, and a front thrust ring, located on an inner surface of the pump casing and at a position near the inlet; so that the front thrust ring and a thrust bearing, which is near an inlet side of the impeller, form an axial thrust bearing assembly; the triangle front support is fixed inside the inlet of the pump casing, and axially passes through a hub aperture of the impeller for supporting an end of a stationary shaft; the impeller is contained in the pump casing, a hub plate is connected to an axially extended part of an inner rotor, so that the impeller and the inner rotor of the canned motor are integrated as a one unit; the containment shell is similar to a cup, of which at the center of the bottom has a blank rear shaft support axially extending inward; a shell flange, which is at the front end of the containment shell, is fitted between the pump casing and a front flange of a corrosion-protection housing in order to prevent the leakage of the corrosive liquid from the canned pump; the stationary shaft is supported at both opposite ends, specifically, the front end of the stationary shaft is supported by the triangle front support, the rear end of the stationary shaft is supported and fixed by the blank rear shaft support; the middle part between the front end and the rear end mated with a bearing for supporting the inner rotor, so that the inner rotor is able to rotate along the stationary shaft; the canned motor of the canned pump comprises a windings stator, the inner rotor, a motor casing, a motor rear casing, and a reinforced bracket; the windings stator inserted inside the motor casing has windings wound around the teeth, a torque is generated from a magnetic interaction between the inner rotor and the windings stator to drive the rotation of the inner rotor, and the inner rotor drives the impeller to rotate and generate hydraulic power, the containment shell protects the windings stator from corrosion caused by the corrosive liquid; the inner rotor is a ring-shape structure comprising a main magnet set, a main yoke and the axially extended part; the inner rotor is encapsulated by a corrosion resistance plastic and forms a sealed rotor resin enclosure; a ceramic bearing is surrounded by the sealed rotor resin enclosure; the axially extended part of the inner rotor is connected to the hub plate, so that the inner rotor and the impeller are combined as a complete unit; the motor rear casing is in the shape of a circular disc; the permanent magnet canned motor pump characterized in that the permanent magnet canned motor pump has a corrosion-protection housing, especially in high temperature, toxic, flammable and corrosive liquid transferred application; the blank rear shaft support axially extending inward is supported from the outer surface by a shaft rear metal support of the motor rear casing, the blank rear shaft support and the shaft rear metal support are closely attached to each other; and on the verge the blank rear shaft support has a rear thrust ring which is mated with the ceramic bearing of the inner rotor to form an axial thrust bearing; the stationary shaft is made of corrosion-resistance and abrasion-resistance ceramic material; the canned motor of the canned pump has a corrosion-protection housing; the motor casing is a cup shaped structure with an aperture at a rear side, and the windings stator is inserted inside the motor casing; the motor rear casing has vertical cooling fins, a terminal box and the shaft rear metal support; the shaft rear metal support axially extended inward through the aperture of the motor casing to offer strongly support to the stationary shaft; and the windings stator is electrically connected to terminals of the terminal box by wire passing through the aperture; the reinforced bracket is a column with an opening at both ends, made of corrosion resistance plastic, the bottom part of the reinforced bracket is a blanket foot plate which is a flat plate; a ring rib divides the inner space of the reinforced bracket into a front inner space and a rear inner space; the motor casing fitted in the front inner space and the motor rear casing fitted in the rear inner space are combined as a complete unit as the corrosion-protection housing; and the front flanges of the corrosion-protection housing are formed by a bracket front flange of the reinforced bracket and a pump side flange of the motor casing; and tapped holes are formed on the front flange for tightly combining to the pump casing, and the front flange is arranged against the back side of the shell flange of the containment shell for sealing and for preventing the leakage of corrosive liquid from the canned pump; a front end of the reinforced bracket pressing against the pump casing is adapted to prevent the permeation of the chemical drops; the corrosion-protection housing is firmly mounted by the blanket foot plate of the reinforced bracket; in addition, the reinforced bracket is long enough so that a rear end of the reinforced bracket covers the terminal box and the cooling fins of the motor rear casing.