Objective: Establishing the Quality Assurance (QA) standardization and digital analysis system of linear accelerators (linacs) is an effective way to improve the level and quality of radiotherapy. Methods: Based on the Pylinac function library, a QA digital analysis system is built with the Django framework and the MySQL database structure. The stability and practicability of the system are evaluated through clinical tests. Results: The QA digital analysis system can substantially reduce the time of calculation and analysis in the QA process, while facilitating the monitoring and review of linac operation. Moreover, it can help new physicists in the radiotherapy department to master the QA process quickly. Conclusion: The QA digital analysis system not only simplifies the QA workflow and improves the working efficiency, but also promotes the QA standardization for the treatment system of radiotherapy linacs.