In this study， a systematic study was carried out on the influence of epitaxial growth and chip preparation process on the reliability and accelerated lifetime prediction of AlGaN-based deep ultraviolet LEDs. The impact of Al component in Quantum Barrier （QB）， Al component in Electron Barrier Layer （EBL）， and different table areas of the same size chip on the reliability of deep ultraviolet LED were explored. The Al fraction was determined to be 74% for the QB structure and 75% for the EBL structure with a table area of P68. Thermal and electrical stress aging tests were designed for the optimised deep-ultraviolet LEDs， and the lifetime of the deep-ultraviolet LEDs was predicted by combining the Arrhenius model， the inverse power-law model， and the exponential least-squares fitting. The experimental results showed that with the increase of electrical and thermal stress， the reliability of deep-ultraviolet LEDs decreased， the Arrhenius model predicted the lifetime of 5 027 hours， the inverse power law model predicted the lifetime of 5 400 hours， and the actual lifetime of the deep-ultraviolet LEDs under the normal operating current of 40 mA was 5 582 hours， and the predictive accuracy of the inverse power law model was improved by 6.7% over the Arrhenius model. By shedding light on these crucial factors influencing the reliability of deep ultraviolet LEDs， the study laid a robust theoretical groundwork. This groundwork would not only facilitate further exploration into reliability enhancement，but also pave the way for widespread application and adoption of deep ultraviolet LEDs in various industries.