In 2016, trial-producing horizontally butted well of gas hydrate was carried out in permafrost area, Qilian Mountain. Reasonable drilling parameters and mud formula have been made according to the different well sections. Precise docking has been realized under small curvature radius by using the MWD technology and SmartMag target-hitting guide system. Drilling technology of horizontally butted well has been successfully applied to gas hydrate trial-producing and good results has been achieved. The drilling construction of horizontally butted well for gas hydrate trial-producing is different from that for dissolvable minerals, which requires a higher accuracy on connection and is also more difficult to be put into effect. This paper mainly introduces the drilling construction technology of horizontally butted well for gas hydrate trial-producing.