Abstract: The 4th generation clinker cooler with middle roller crusher has many advantages, such as high heat recovery efficiency, excellent cooling effect, low power consumption and high generating capacity, etc. This advanced equipment has been widely used in the new or modified clinker production line. This article comprehensively introduced the design details of technical transformation process from the 3rd generation cooler to the 4th generation cooler, including selection principle of the first part and second elevation of the cooler, the arrangement of cooling fans and hydraulic station, connection of the hot air duct, installation of the device used to eliminate clinker block, maintenance plan of the roller crusher, and transformation of trough conveyer and related chutes.