The invention provides a semicoke cooling system. The semicoke cooling system comprises a primary cooling device and a secondary cooling device, wherein the primary cooling device comprises a heater exchanger, the heat exchanger is arranged below a rotary kiln and is communicated with the rotary kiln; and the secondary cooling device comprises a cooling screw conveyor, and the cooling screw conveyor is communicated with the primary cooling device. The primary cooling device containing the heat exchanger is arranged below the rotary kiln, so that high temperature power equipment between the rotary kiln and a high temperature heat exchanger is eliminated, equipment failure caused by high temperature is avoided, equipment running stability is improved, and semicoke produced by the rotary kiln can conveniently directly fall into the heat exchanger by virtue of gravity to be subjected to primary cooling; then the semicoke is further subjected to secondary cooling by virtue of the cooling screw conveyor, and a semicoke material fully rolls in a material pipe under the action of a screw conveying shaft and is fully contacted with a cooling surface, so that final coke discharging temperature is consistent, and further quality of the cooled semicoke product is improved.