Offshore oilfield A belongs to the middle and deep layers’ reservoir, and the poor quality of seismic data has led to the uncertainty of fault location. Regarding the contradiction between the actual production performance and the understanding of fault location in the 6 well area of the oilfield, through applying material balance methods, pressure response characteristics, and injection production efficiency relationships, the direction of fault position adjustment in the 6 well areas were qualitatively determined. Through numerical simulation sensitivity analysis experiments, quantitative adjustment of fault position was achieved. Compared to conventional methods, this method is more accurate in adjusting the direction and distance of fault positions. Based on the adjustment of fault location, the injection production relationship in the 6 well area was adjusted, which significantly improved the development effect of this well area. This method can provide a basis for solving development and production problems in similar middle and deep reservoirs. This research innovatively proposes a production dynamic analysis and numerical simulation study based on reservoir engineering theory and numerical simulation, effectively solved the problem of uncertain fault location in middle and deep layers’ reservoirs, and providing a basis for solving development and production problems in similar reservoirs.