In the process of sustainability information assurance, risk assessment serves as a core component providing a critical foundation for forming final assurance conclusions. Constructing a scientifically robust risk assessment indicator system enhances the operability of sustainability information assurance, promotes the expansion of the assurance scope from financial materiality to impact materiality, and ultimately achieves a holistic evaluation of an enterprise’s sustainable development.

Drawing on the Corporate Sustainability Disclosure Standard—Basic Standard (Trial) and the Sustainabi- lity Information Assurance Services Standard No. 6101—Basic Standard (Trial), and integrating the ISSA 5000 assurance standard with the dual materiality principle, this paper systematically analyzes the fundamental principles, model construction, indicator configuration, and subsequent response measures for risk assessment in sustainability information assurance. First, it proposes a fundamental risk assessment principle that synergizes the disclosure level with the disclosure assertion level. Second, it constructs a comprehensive evaluation tool comprising an F-PSR model based on the dual materiality principle and a risk assessment quadrant matrix. Building on the risk assessment conclusions and incorporating China’s sustainability information assurance practices, it designs response procedures and evidence collection plans that are both principled and operable. Furthermore, the study selects four case enterprises for empirical validation, achieving an organic integration of international assurance standards within China’s institutional setting.

The innovations of this paper are as follows: First, it systematically analyzes the fundamental principles, model construction, indicator setting, and subsequent response measures for risk assessment in sustainability information assurance, thereby enhancing the logical rigor and practical guidance of the risk assessment system. Second, it transcends the limitations of traditional audit risk models in their applicability to sustainability information assurance and, to a certain extent, expands the application boundaries of the existing PSR model at the micro-enterprise level and within the assurance field. Third, it constructs an assurance risk assessment system suited to China’s local institutional environment and developmental stage, and responds to the practical challenge of the lack of a systematic framework for assurance methods during the current transition of sustai- nability information from voluntary to mandatory disclosure, achieving an organic integration of international assurance standards with China’s institutional context.