With the promotion and development of digital finance, the degree of digitalization has an increasingly significant impact on the banking business, which cannot be ignored in the operation of commercial banks. Therefore, establishing a digitalization bank profitability system model is of great significance for the sustainable development of banks and digital finance. This article selects 6 Chinese state-owned banks from 57 listed banks in the A+H stock market as samples, constructs a digital indicator system and evaluation model for banks through the literature review method, and uses simulation training to explore the effectiveness of BP neural network in evaluating the impact of digitalization on bank profitability. The aim is to provide a reference for the evaluation of financial statement information of other banks and other factors affecting bank digitalization. The innovation of the article lies in the innovative use of the entropy weight coefficient of variation method to establish a digital evaluation system model, which utilizes the data itself to objectively establish an evaluation system, incorporate the established digital system into the black box model of the BP neural network model to study the impact of changes in digitalization on banking operations.