A permanent magnet linear piston pump comprising a piston body, a cylinder body, a permanent magnet assembly and an electromagnetic coil; wherein a piston cavity is formed in said cylinder body by an axial columnar accommodating cavity, said piston body being disposed in said piston cavity by a liquid sealing movable fit mode, a one-way inlet valve and a one-way outlet valve being disposed on an end face of said piston cavity opposite to an end face of a piston, a coil supporting member being disposed at an outside surface of said cylinder body, said electromagnetic coil being axially and distributively wound around said coil supporting member into a barrel shape, an axial sliding slot being formed on said side surface of said cylinder body where said permanent magnet assembly is disposed, a connecting post being radially disposed on a side surface of said piston body to fit in with said sliding slot by a clearance fit mode, said connecting post penetrating through said sliding slot, characterized in that the permanent magnet assembly is disposed on at least one side surface of said cylinder body, said permanent magnet assembly including an inner mounting plate and an outer mounting plate disposed parallel to said side surface of said cylinder body, said inner mounting plate and said outer mounting plate being made of a permeability magnetic material, an inner magnetic body and an outer magnetic body being respectively disposed on opposite surfaces of said inner mounting plate and said outer mounting plate, said inner magnetic body and said outer magnetic body being disposed oppositely and providing contrary magnetic poles at opposite faces thereof,, a barrel wall formed by said electromagnetic coil being disposed between said inner magnetic body and said outer magnetic body, said connecting post is in connection with and in linkage with said inner mounting plate and said outer mounting plate. wherein a piston cavity is formed in said cylinder body by an axial columnar accommodating cavity, said piston body being disposed in said piston cavity by a liquid sealing movable fit mode, a one-way inlet valve and a one-way outlet valve being disposed on an end face of said piston cavity opposite to an end face of a piston, a coil supporting member being disposed at an outside surface of said cylinder body, said electromagnetic coil being axially and distributively wound around said coil supporting member into a barrel shape, an axial sliding slot being formed on said side surface of said cylinder body where said permanent magnet assembly is disposed, a connecting post being radially disposed on a side surface of said piston body to fit in with said sliding slot by a clearance fit mode, said connecting post penetrating through said sliding slot, characterized in that the permanent magnet assembly is disposed on at least one side surface of said cylinder body, said permanent magnet assembly including an inner mounting plate and an outer mounting plate disposed parallel to said side surface of said cylinder body, said inner mounting plate and said outer mounting plate being made of a permeability magnetic material, an inner magnetic body and an outer magnetic body being respectively disposed on opposite surfaces of said inner mounting plate and said outer mounting plate, said inner magnetic body and said outer magnetic body being disposed oppositely and providing contrary magnetic poles at opposite faces thereof,, a barrel wall formed by said electromagnetic coil being disposed between said inner magnetic body and said outer magnetic body, said connecting post is in connection with and in linkage with said inner mounting plate and said outer mounting plate.