The invention discloses a seed drying system. The seed drying system comprises a pre-storage tower (1), a drying tower (2), a cooling tower (3), a hot air blowing device and two cold air blowers, wherein the pre-storage tower (1), the drying tower (2) and the cooling tower (3) respectively comprise a tower body, a feeding port arranged at the upper part of the tower body, a discharging port arranged at the lower part of the tower body, an air inlet cavity arranged outside the tower body, as well as an air inlet pipe (4) and an air outlet pipe (5) arranged inside the tower body, the lower surfaces of the air inlet pipe (4) and the air outlet pipe (5) have vent holes (6), one end of the air inlet pipe (4) is communicated with the air inlet cavity, the other end of the air inlet pipe (4) is sealed, and two ends of the air outlet pipe (5) are communicated with air outside the tower body. The seed drying system has the beneficial effects of satisfying the requirements on the drying operation of a large number of seeds which needs to be completed in a short period of time during a seed harvesting period, and being high in degree of automation, simple and convenient to operate, small in occupied area, uniform in drying effect and high in heat exchange efficiency.