The paper introduces rotary steering drilling tool developed by authors' research group in detail. The tool is composed of four modules of the power, measurement, control and executive mechanism. The composition and detailed mechanical structure of stable platform section and executive mechanism have been revealed. The main units and field test in the process of research have been introduced briefly, including disc valve friction in executive mechanism, test device for back up plate force, indoor synthesis waterpower test and field test of the tool. Key difficulties of design, machining, install and field test in research has been summarized. The tool has realized drilling function, and has been developed better for industrialized application.
