Long-distance directional drilling pipeline back-pulling mud circulation construction process

The invention relates to a long-distance directional drilling pipeline back-pulling mud circulation construction process. The long-distance directional drilling pipeline back-pulling mud circulation construction process comprises the following construction steps that S1, preparation before construction is conducted, specifically, an underground pipe is detected firstly, and a working well and a receiving well are formed; S2, mud preparation is conducted, specifically, proper mud is prepared for standby application; S3, reaming construction is conducted, specifically, a reamer is driven by a drilling machine and a drill rod to move back and forth along a guide hole; S4, first-time back-pulling pipe pulling construction is conducted, specifically, the outer side of a first pipeline is sleeved with a casing pipe, then the end of the casing pipe is connected with the reamer, a pipe pulling machine is started to start to pull back the casing pipe, and the mud in the step S2 is pumped into a drill hole in the casin