Well 19H of Zhongjiang is a long horizontal well with designed depth of 3830m and 990m in the horizontal section. The fracture develops in this district with wide spreading well wall instability and block falling. The design of the second open hole section makes the wall instability even worse, the sand bridge may be formed by local accumulation of falling blocks in the well bore to cause drill rod sticking. The reasons of drill rod sticking are analyzed in this paper, the corresponding preventive measures are put forward in optimization of drilling fluid performance, drilling tools and drilling tool assembly for horizontal section as well as reinforcing well bore clarification. The later sidetracking construction is successfully completed, which provides some valuable experiences for drilling work in this district.