In order to solve the important problems occurring inoptimizing water resources engineering schemes, such as consistency and non － dimensionalization of fuzzy qualitative and quantitative evaluation indexes, difficulty in determining weights of indexes, little difference of comprehensive evaluation index values and notable subjective influence on optimized results, a projection pursuit method is developed, named FPRM － PP(fuzzy preferential relation matrix － projection prusuit). An optimal fuzzy consistency judgement matrix A, consistency index function and its critical values are presented. A new algorithm is proposed to check and modify the consistency of matrix A and to compute the preferential values of each scheme at the same time using accelerating genetic algorithm improved by the authors. The results from theoretical analysis and a case study show that: FPRM － PP is visual, practical; modificative range of matrix is less; its result is stable and of high precision. 