Abstract: TDS - 9S top -driving drilling equipment is the thirdgeneration of the top -driving drilling equipment that usesvariable frequency electric motor which is developedrecently by Varco. It is sall,light and easy - to - move,hascompact structure,excellent performance and its operationis reliab1e. This paper describes its performanceparameters and the main structures and their functions,andsums up its drilling operation characteristics in theWestern part of China.