A cement factory plans to change the kiln size from ?4.8m×74m to ?4.3m×74m. In order to reduce the cost of transforming, the reconstruction scheme adopted the original supports and tyres, redesign and manufacture the double loose pads system. This paper focuses on the double loose pads system structure design, machining, on-site installation and daily operation and maintenance. The double loose pads system is mainly composed of inner and outer pads, retaining rings,  transition sleeve, etc. The design should ensure a certain gap value and slippage between shell, tyre and retaining ring. During maching, the transition sleeve should be stress-relief annealing treatment; when installing, the pads system and tyre must be pre-assembly with large sections of the shell; during maintenance, it should pay attention to the lubrication and gap value detection of the pads system and replace the pads in time. The transformation took 4 months. The rotary kiln runs stably after being put into operation, and the expected goal of the transformation has been achieved.