Well Gucheng-7 is the first drilling well in Tadong block of Daqing oilfield. To increase the success rate of drilling, shorten drilling period and reduce drilling cost, a lot of calculation, statistical analysis and screening were made on the designs of well structure, BHA, bit optimization and the application of torsion impact apparatus in combination with PDC bits, the real drilling speed was greatly improved. The average penetration rate was 4.68m/h, 55.48% higher than that in well Gucheng-6 of 3.01m/h; drilling cycle is 152.44d, 86.8d less than well Gucheng-6. The practice shows that the design of well Gucheng-7 is consistent with the geological conditions in Tadong block with large improvement of drilling speed, short drilling period and low drilling cost.