At present, the grate-kiln is the main process of oxidation pellet production in China, due to its continuous and closed high temperature characteristics, some parameters in the production process cannot be detected in real time, which will bring difficulties to the automation and operation improvement of the process, and will make the production line in a passive control state for a long time. In view of the fact that the automatic control of the fabric thickness and the fill rate of the rotary kiln plays an important role in the automatic production of pelletizing, a typical pelletizing production process of an enterprise is taken as the object, and an automatic control method for the fabric thickness of the chain grate machine and the fill rate of the rotary kiln is established based on the optimization of on-site operation data and control methods. The results show that the machine speed value calculated based on the specific gravity K value of the green pellet pile can be in good agreement with the actual operation calculation value, and the fill rate based on the theoretical calculation has good reference significance, and in order to achieve stable operation of 7%~8% fill rate, the ratio of fill rate to rotation speed should be controlled at 1.27 ~1.45. The results can provide guidance and reference for the automatic control of pelletizing production.