In order to effectively select a reasonable way to improve the flood control standard and probe into the impact of the levee heightening on waterfront development land in the metropolis, selecting transportation conditions, basic facilities, environmental conditions, and urban planning four factors, the impact assessment model of the metropolis levee heightening project on the waterfront development land is constructed, by using the Delphi method, the center-point triangular whiten weight function and the fuzzy comprehensive assessment. The empirical study of the levee heightening project in City Y shows that the metropolitan levee heightening project will have a certain negative impact on the development land of waterfront. It is suggested to optimize flood control development scheme, or select other peripheral projects, and establish comprehensive non-engineering methods.