Abstract: The development of large-scale well cluster fields in Dagang Oilfield encounters problems such as the high risk of collision between wells, difficulties in trajectory optimization and drilling acceleration, etc. According to the idea of integrating geology and engineering, the key technologies involved were studied, including well pattern deployment, wellbore trajectory and anti-collision design, casing program, and supporting drilling acceleration tools. This paper established the wellhead-target matching relationship, the priority sequence of profile type design, the V-shaped design rule for kick-off points, the casing program, and the acceleration process template of one-trip drilling. In this way, efficient drilling technologies were developed for the large-scale well cluster fields in Dagang Oilfield, and were applied to the Dagang Oilfield. The large-scale well cluster field Gangxi No.2 is the largest among the onshore well cluster fields in Dagang Oilfield. In this well cluster field, safe and scaled development of 56 wells were achieved, with a cost saving of CNY 12 million in aspects such as land expropriations for well sites and drilling relocation, and an average single-well drilling cycle of 4.42 d, and rate of penetration (ROP) of 48.64 m/h. The research and applications showed that the developed technologies displayed outstanding performance in raising the utilization rate of well sites, shortening the drilling cycle, increasing ROP, and lowering the costs. The results can provide technical support for the profitable development of Dagang Oilfield.