Abstract: Medium paddy field ploughing and rake grader is a kind of agricultural machinery with 29.4 kW power tractor as power of paddy field plowing and raking and it is an indispensable agricultural machinery tool in modern agricultural production.A set of high efficiency and multi-performance auxiliary mechanism was designed according to its working performance and characteristics.Auxiliary mechanism not only provided installation platform for cutter shaft system and transmission system of rake grader，but also provided hanging device for connection between plough grader and tractor.At the same time，whole machine has four functions of rotary tillage，broken soil，flat soil and stubble，so auxiliary mechanism has a variety of performance and is simple compared with many kinds of single performance machine.