The quality of well cementing is crucial for the safety of oil and gas wells, ensuring the integrity of oil and gas reservoirs, improving the efficiency of water injection, and reducing the development cost of oil and gas fields. Currently, the evaluation of well cementing quality can only qualitatively determine whether it is qualified, ignoring the impact of special well sections on the overall quality of well cementing. It cannot provide comprehensive quantitative indicators for the quality of well cementing in the entire well section, which is not conducive to the comprehensive evaluation of the effectiveness of well cementing operations. This article provides a method for characterizing cementing quality, which comprehensively considers the upper and lower limits of cementing quality qualification rate, the stability of cementing quality logging data, and invents the cementing quality index, which can comprehensively quantify the cementing quality of the entire wellbore section. Taking XX well in a certain oilfield as an example, the model was used to evaluate the cementing quality of the first well section. The calculation results showed that the cementing index of the first well section of XX well was 145.4. The cementing quality characterization method proposed in this article can provide theoretical basis for evaluating the effectiveness of oilfield cementing operations, later oilfield water and gas injection, and wellbore integrity assessment before reservoir transformation.