According to the concrete task for the groundwater resource system in Jinan to manage and study the protection of springs and water supply, a multi-purpose management model for the groundwater resource system has been built up mathematically in this paper. Using the fuzzy mathematical theory, a fuzzy-weight method is proposed. It can solve the incomparabil-ity and the primary and secondary between various objectives at the same time. The theoretical analysis and a case study show that the multi-purpose management model and the fuzzy-weight method are rational and effective.