Abstract: The half way rotary drilling technology is a technical extension based on conventional sliding steerable drilling. The principle of this technology is to separate the torque of the lower drilling tool from the upper drilling tool, so that the upper drill string can be rotated and sent to the drill at low speed. while the lower drilling tool performs the function of conventional sliding directional drilling. In this way, the control ability of conventional steerable drilling trajectory and the extension ability of horizontal section can be greatly improved at low cost. It has broad application prospects. Based on this technology, an electrically controlled semi-rotary steerable drilling tool was developed. The electrically controlled semi-rotary steerable drilling tool was installed near the drill bit end of the drill string of conventional sliding directional drilling. The ground signal transmission device sent a drilling fluid negative pulse sequence command. After receiving the command, the tool performed the drill string torque separation and combination action. It should be pointed out that the control of the anti-torque after torque separation is the key technology of the tool. Usually, the friction torque between the drill string and the well wall is used to counteract the anti-torque, but when the torque surges, the anti-torque cannot be balanced. The electrically controlled semi-rotary steerable drilling tool can effectively resist the anti-torque and stabilize the tool face by adding an anti-reverse torque stabilizer and a torque absorption and energy storage assembly. The four-well field test of the electrically controlled semi-rotary steerable drilling tool showed that it can greatly alleviate the support pressure, reduce friction and drag, and improve the drilling pressure transmission efficiency. The tool has the ability to control the anti-torque. After the torque is separated, the tool face remains stable and ROP is improved.