Accurately calculating the carbon footprint of products relies on an electric carbon factor with appropriate calculation granularity and time-varying characteristics. The calculation and application of time- and area-specific electric carbon factors have become a research hotspot in the industry, which helps refine the calculation of the electric carbon factor, enrich its application scenarios, and strengthen the management of product carbon footprint accounting. This study analyzes the important role of time- and area-specific electric carbon factor in product carbon footprint accounting, and establishes a calculation method and application process for the factor based on actual production and operation of power systems. Taking Jiangsu Province as an example, the detailed calculation process of the time- and area-specific electric carbon factor was demonstrated, and the spatiotemporal variation feature of the factor was analyzed from the aspects of seasonal changes, differences in typical days at different time periods, and distribution of different prefecture level cities. Furthermore, the application prospects of the time- and area-specific electric carbon factor in product carbon footprint accounting were discussed from the aspects of optimizing the basic parameters of product carbon footprint accounting, improving carbon footprint accounting standards and carbon reduction policy systems, and promoting greener and low-carbon product production models. It is recommended to take actions in promoting the application of the time- and area-specific electric carbon factor, strengthening the continuous online monitoring of thermal power carbon emissions, developing product carbon footprint accounting standards, and establishing an internationally aligned product carbon footprint accounting certification system, thus to comprehensively strengthen the product carbon footprint accounting in China.