This study delves into the critical role of Dazhimian technology in enhancing the evaluation of internal audit in universities and its optimization process. Firstly, a balanced scorecard-based internal audit performance evaluation system for universities was constructed, which covers four dimensions, namely, functional performance, service object, internal management process, learning and growth, and is further refined into 25 evaluation indexes. Then, the entropy weight-TOPSIS evaluation model was used and combined with actual data for empirical analysis, thus effectively measuring internal audit performance. Specifically for the case study, College F as a research subject shows significant performance improvement. The functional performance weight is as high as 0.3574, significantly higher than other dimensions, reflecting its outstanding performance in improving internal audit performance. Comprehensively analyzing the horizontal and vertical comparisons, HEI F has been improving its internal audit performance and its relative closeness is leading in all dimensions. In addition, we find that the quality of internal auditing in HEIs has a significant positive impact on profitability, operational capability and sustainable Development, further confirming the importance of optimizing the internal audit system. This study provides an effective technical tool for evaluating internal audit and its optimization in universities and valuable references and lessons for other universities.