The invention provides an ultra-fine grinding system for cement production. The ultra-fine grinding system for cement production comprises following components of an ultra-fine grinding machine (1), a dynamic powder selecting machine (2) arranged in the ultra-fine grinding machine (1), a drying and feeding system connected with one side of the ultra-fine grinding machine (1) and an oil pressure system (4) connected with the other side of the ultra-fine grinding machine (1). The ultra-fine grinding machine (1) comprises a motor (1-1), a speed reducer (1-2) connected with the motor (1-1), a grinding disc (1-3) disposed in the ultra-fine grinding machine (1), grinding rollers (1-4) connected with the grinding disc (1-3), an air inlet (1-5) formed in the lower portion of the ultra-fine grinding machine (1) and an impurity discharging outlet (1-6) formed in the lower portion of the ultra-fine grinding machine (1). A fine powder outlet (2-1) is formed in the upper portion of the dynamic powder selecting machine (2). By means of the ultra-fine grinding system for cement clinker processing, the cement fineness is greatly improved, so that the hardness and durability of concrete products are improved and the quality of construction projects is guaranteed. By means of the drying and feeding system, the influence on feeding quantity due to increase of material moisture in the rainy season can be avoided, and the smooth feeding is facilitated.