For a long time, the cultivation and assessment of the practical application ability of piano in music education has been an important issue that people are constantly concerned about and trying to solve. The research uses the evaluation method based on fuzzy neural network to conduct the study, first of all, from the basic skills, performance skills as well as creative skills in three aspects of the construction of the students’ piano skills level index system, through the objective weight entropy weighting method to determine the weight of the index system on the students’ piano skills were assessed and analyzed, and got the indexes of the importance of the order of the subjective weighting order of the creation of skills (C, 0.471) > performance skills (B, 0.384) > basic skills (A, 0.145). 0.384) > basic skills (A, 0.145). After the selection of sample data, standardization of sample data and simulation training of the network model, the experimental results show that the application of the fuzzy neural network model for the evaluation of piano skill level is effective and feasible. The temporal accuracy and cognitive accuracy of piano playing were fused to quantitatively assess the brain function. The experimental results show that the brain function scores obtained with this method can effectively indicate that the students’ brain function increases with the increase of practice time and decreases with the increase of difficulty.