Improving the discretionary benchmark for administrative penalty is an important measure to solidly promote the rule of law in administration. The Twentieth National Congress of the Communist Party of China(CPC), which explicitly proposes‘improving administrative discretionary benchmark’. In the field of water administrative penalty, benchmark is an important administrative self-regulatory means to standardise the discretionary power of water administrative penalty and ensure fair and reasonable law enforcement. Upon reviewing the current text of the water administrative penalty discretionary benchmark , several issues have been identified, such as the selection of consideration elements for illegal circumstances in the relevant technical structure being insufficiently comprehensive, the classification of penalty effects being inadequately reasonable, and the absence of certain exemption clause, making it difficult to meet the needs of water law enforcement practice. In light of the particularity of water-related illegal activities, the discretionary benchmark for water administrative penalty can be improved in three aspects. In terms of detailing circumstances, dynamic adjustment techniques can be introduced, taking into account environmental factors and socio-economic factors, while pre-setting substantive consideration elements and penalty classifications; in terms of effect classification, the application paths of legal principles can be explored, introducing the principles of legality in discretion and proportionality to clarify the classification techniques; in terms of setting exemption clause, restrictive rules for exemption clause should be improved, standardising the establishment, application conditions, and supervision methods of escape rights.