The anti-overturning stability calculation of hydraulic structures is a core issue in engineering design.However,the ambiguous division of stabilizing and overturning moments in design codes results in non-unique calculation outcomes,even when the same code or different ones are adopted for anti-overturning stability calculation.In response to the ambiguous division of stabilizing and overturning moments in current codes,this paper analyzes the controversial points of anti-overturning formulas in the Technical Specification for Retaining and Protection of Building Foundation Excavations,Specifications for Design of Highway Subgrades,Code for Design of Hydraulic Structures of Shiplocks, and Code for Design of Retaining Walls for Hydropower Projects,and proposes a theoretical framework centered on base stress analysis.The study demonstrates that anti-overturning stability is essentially attributed to the control of base tensile stress.By analyzing the distribution of the compressive area of base stress using the material mechanics method,the critical ratio between stabilizing moments(vertical load moments)and overturning moments(horizontal load moments)is derived.This ratio is an indirect characterization of the base stress distribution state,which ultimately verifies the rationality of the formulas in the Code for Design of Retaining Walls for Hydropower Projects.The research results provide a theoretical basis for unifying the calculation standards of anti-overturning stability and recommend taking base stress verification as the criterion for anti-overturning stability.