This paper establishes a model that would allow China’s oil and gas enterprises to scientifically evaluate and measure their low-carbon level and status. It considers various characteristics of China’s oil and gas enterprises and the implications of low-carbon development, and is based on an overall analysis of factors that influence the reduction of carbon emissions. In view of low-carbon economic theories and the general principles of an evaluation index system, a comprehensive system for measuring the low-carbon status of China’s oil and gas enterprises has been developed. This measurement system is comprised of four main criteria (energy structure, energy utilization, carbon emissions and utilization, and low carbon management) as well as thirty indexes. By the Delphi method and the analytical hierarchy process (AHP), the weight of the rules hierarchy and indexes hierarchy were determined. The standardized indexes were then integrated using a linear weighted sum formula, and a comprehensive formula for index measurement was established. Taking into account the status of low-carbon development in the petroleum and petrochemical industry at home and abroad, an evaluation criterion is proposed comprising four levels: ideal low-carbon, economical low-carbon, medium-carbon and high-carbon, whose values were organized within the settings of [0, 1].