A method for manufacturing a stator for an electric water pump may be used for manufacturing the stator used in the electric water pump. In the electric water pump which includes stator assembly for an electric water pump, wherein the stator assembly including a plurality of core-insulator assemblies generates a magnetic field according to a control signal and a rotor is rotated by the magnetic field generated at the stator assembly to pressurize coolant, the method for manufacturing the stator assembly may include a) stacking a plurality of pieces made of a magnetic material to form a core stack, b) molding an insulator to the core stack, c) coiling a coil to the insulator to form a core-insulator assembly so as to form a magnetic path, and d) connecting the respective core-insulator assembly in an annular shape in sequence to form the stator assembly.