The invention discloses a grinding mechanism in a chloro oxytetracycline airflow drying system. The grinding mechanism comprises a grinding table, a grinding sleeve, a material guiding plate, a stop ring, a motor and a workbench provided with a feeding port. The stop ring is fixed to the workbench and located on one side of the feeding port. The grinding table is rotationally arranged in the stop ring and connected with a rotating shaft of the motor. The grinding sleeve is arranged above the grinding table. A grinding gap is formed between the grinding sleeve and the grinding table. A discharging notch is formed in the stop ring and located in one side of the feeding port. The material guiding plate is fixed to the side wall of the discharging notch, and one end of the material guiding plate extends into the feeding port. The grinding mechanism is simple in structure and convenient to use. The chloro oxytetracycline pulverized through a pulverizer enters the grinding sleeve in the grinding mechanism, the chloro oxytetracycline enters a hot air pipeline of the drying system after being ground by the grinding mechanism, and the drying effect is good.