With high control accuracy requirements on the wellbore trajectory, Xushen 21-Ping 1 well was completed at the drilling depth of 4955m with 905m drilling in transverse direction through the volcano rock reservoirs, and the sidetracking was successful under the condition of rock drillability of grade 8 in mudstone section, which laid the foundation for the subsequent construction. The paper sketches the well structure and trajectory profile design, analyzes the difficulties in well trajectory control and introduces in detail the wellbore trajectory control on the kick-off section, sidetrack section and horizontal section. The successful well drilling provides valuable experience for the horizontal well construction in this area.