Abstract: The hydraulic microhabitat of spawning ground of Schizothorax Prenantihabitat is a multi-indicator set.What type of ecological spur dike angle is reasonable in the downstream water-reducing reach after the construction of Jiangshe dam? How to measure whether the water area after the restoration of ecological spur dikes still has the hydraulic characteristics of spawning ground? These issues involve the measurement and representation of more fuzzy concepts.Up to date, the engineers only rely on the accumulation of practical experience or model test to guide the ecological spur dikes angle of different rivers.In this paper, the similarity model of hydraulic microhabitat in habitat spawning ground was established by vague set after restoration, and the similarity standard for microhabitats in spawning grounds after restoration of the habitat of Schizothorax Prenantiwas constructed with reference to foreign spawning ground restoration cases.Based on the two-dimensional hydrodynamic model of average water depth, hydraulic microhabitat of habitat spawning ground of Schizothorax Prenanti in the repaired river section of Jiangshe dam were simulated in terms of water depth, flow velocity, vorticity,and other factors.The effects of different angles and types of ecological spur dikes were studied on the hydraulic microhabitats of habitat spawning ground of Schizothorax Prenanti.Then, the improved vague set was used to verify the repair effect of ecological spur dikes.The research results indicated that the orthogonal L-shaped ecological spur dikes had the best repaired effect when there was a small flow and a certain distance between ecological spur dikes.The results also demonstrated that a larger ratio of the effective length of ecological spur dikes to the effective width of the river facilitated a higher similarity of hydraulic microhabitats after restoration.