In view of the fact that pellet producers are generally facing shortage of high quality pelletizing concentrate resources supply, fluctuating varieties and properties of raw materials, resulting in difficult production control and unstable product quality, while the traditional chain grate-rotary kiln process has bottlenecks such as poor raw material adaptability, relatively single product, and rotary kiln prone to knotting. Therefore, theoretical and technological innovation is carried out from many aspects such as low cost wide caliber, diversified pelletizing products, stable and clean production process of pelletizing raw material resource supply, in order to solve the key problems that bother the pelletizing industry, promote the smooth operation of the large chain grate-rotary kiln pelletizing production line, improve the technical level of “concentrate” preparation technology for pellets in China and promote the low-carbon and high-quality development of the iron and steel industry.