With the advent of the era of big data, enterprises are faced with the challenge of how to effectively utilize massive data to optimize financial management and decision-making. The purpose of this study is to explore the financial data analysis model based on big data and its design and application in decision support system. Through questionnaire data collection, the paper analyzes the enterprise’s cognition of big data technology and its application in financial data analysis. On this basis, this study develops a financial data analysis model, which improves the accuracy and reliability of the model through data preprocessing and efficient analysis methods. The application of the model in decision support system shows that it can provide timely and accurate financial information for enterprise management and support more effective decision-making. At the same time, the main challenges encountered in the implementation process and the corresponding solutions are also discussed. This study provides new insights into theory and practice and points to possible directions for future research.