The invention discloses a synchronous phase modifier stator cooling system, which comprises a water cooling system and an air cooling system arranged on a stator and a rotor, wherein the water coolingsystem comprises a stator shell, a stator iron core and a stator winding; the stator shell coats the stator iron core; the stator iron core is wedge-shaped, a rectangular groove is formed in the small end of the wedge, the stator winding is installed in the rectangular groove, and vent grooves are formed in the two side faces of the wedge; a solid flat copper wire and a hollow flat copper wire are wound on the stator winding; one end of the hollow flat copper wire is connected with a main water inlet collecting pipe, the other end of the hollow flat copper wire is connected with a main wateroutlet collecting pipe, the other end of the main water inlet collecting pipe is connected with a water receiving box, and cooling water in the water receiving box enters from the main water inlet collecting pipe and flows out from the main water outlet collecting pipe; the air cooling system comprises a rotor with fans installed at the two ends, an air gap is formed between the rotor and the stator, the fans at the two ends rotate along with the rotor, and air enters the space between the stator and the rotor through the air gap. The problem that an existing large synchronous phase modifier stator is poor in heat dissipation effects is solved.