In response to the hydrogen sulfide production issue in the offshore S oilfield, while also considering the enhancement of recovery efficiency, a composite solution approach of "inhibition-activation-enhancement" has been proposed. Based on the principles of molecular ecology and genomic proteomics, a composite system was developed through community analysis, strain screening, agent optimization, and efficacy evaluation. This system is capable of both inhibiting hydrogen sulfide-producing bacteria and activating microbial functions, effectively suppressing the hydrogen sulfide-producing bacteria in the oilfield system while achieving the goal of enhanced microbial oil recovery. A field trial for hydrogen sulfide treatment was conducted at well A07 in the S oilfield in August 2024. The H2S concentration decreased from 50ppm to 9ppm, the SRP concentration decreased from 103 to 10 per ml, a reduction of two orders of magnitude, and the NRB concentration increased from 103 to 105 per ml, an increase of two orders of magnitude, indicating a significant activation effect of the agent on NRB. As of June 15, 2025, the water content in the benefiting well group decreased by 3.1%, with a phase increase in oil production of 6541 cubic meters, and the effective period has reached 6 months and continues to show results, providing a new approach for hydrogen sulfide treatment and enhanced recovery in offshore oilfields.