In order to scientifically evaluate the harmony of human and water, a new firefly algorithm (NFA)-projection pursuit (PP) evaluation model was constructed. The case study of Wenshan Prefecture in 2006-2018 was taken as an example. Eight typical test functions were selected to simulate the NFA, and compared with the simulation results of four optimization algorithms such as teaching leaming based optimization(TLBO). Sixteen indicators were selected from three aspects, namely water resources, economy & society and ecological environment, to construct regional human-water harmony evaluation index system and grading standards. Random interpolation method was used to generate sample construction human water harmony degree evaluation projection between each grading standard threshold. The objective function, obtained by using NFA to optimize the optimal projection vector, constructs the NFA-PP model to evaluate the annual human-water harmony in the study area. The results showed that the NFA optimization effect is better than that of the four algorithms such as TLBO in terms of better optimization precision, extreme value optimization ability and global search ability. The NFA-PP model evaluates the human-water harmony degree as “disharmonious” in 2006-2011, “almost harmonious” in 2012-2016, and “harmonious” in 2017-2018. In the past 13 years, the human-water harmony in Wenshan Prefecture has shown an upward trend, and the upward trend is remarkable.