As a critical decision–support tool for sustainable development in alpine lake watersheds, ecosystem service valuation requires scientifically robust accounting systems to inform environmental management. This study addresses the significant interference caused by multi-source heterogeneity in indicator selection, methodology application, and parameter determination within current valuation systems. We innovatively developed a multi-dimensional accounting framework. Through establishing standardized systems for indicators, methods, and parameters, taking Xingyun Lake as the research area, we systematically elucidated the differential impact mechanisms of accounting elements on valuation outcomes. Empirical results demonstrate that structural differences in indicator systems induce 11.61% of valuation fluctuations. Methodological choices lead to 13.86% of deviations. Insufficient parameter localization generates errors up to 18.48%. The refined framework improved valuation accuracy by 16.22%. This study quantitatively evaluates the influencing factors of ecosystem services and confirms a cascading amplification effect of element sensitivity (parameters > methods > indicators) on valuation outcomes, establishing methodological foundations for alpine lake watershed ecological accounting benchmarks. It has important decision-making reference value for applying ecosystem service function evaluation to sustainable development.