Abstract: The super-torque high-precision indexing rotary device is a key component in large-scale rotor machining, and is often used to achieve precise indexing of parts in large-scale CNC machine tools. In order to improve the indexing accuracy and design efficiency of the indexing slewing device, it is necessary to find out the key factors affecting the accuracy of the indexing device, and to explore the design method of the super-high torque and high-precision indexing slewing device. On this basis, The Matlab sotfware is used to develop Computer Aided Design (CAD) program for indexing device. The program uses the GUI of Matlab software to design the program interface. The parameters of different specifications can be written into the database through the user interface in advance. While the load changes, the parameters of the database can be called at any time. Quickly query replaceable parts to achieve fast design of high-reliability and high-precision indexing rotary devices.