To address the issues of inadequate expansion and low quality of upper leaves in Yunnan flue-cured tobacco, field experiments were conducted using ‘Yunyan 87’ as the test material in Dehong and Lijiang. The effects of three exogenous regulators, forchlorfenuron (KT), zeatin (ZT), and brassinolide (BR), as well as their concentrations and application timings on the expansion and quality of upper leaves were investigated. The results showed that: (1) application on the day of topping was optimal, significantly superior to application 7 days after topping; (2) single-agent treatments were more effective than combined treatments, with 20 mg/L KT showing the best promoting effect on leaf expansion. In Dehong, the leaf length and width increased by 9.85%-32.90% and 23.34%-41.27%, respectively, compared to the control. In Lijiang, the leaf area increased by 16.27%-31.30% compared to the control (water); (3) regarding appearance quality, the order of effectiveness was 10 mg/L KT> 20 mg/L KT> 1 mg/L BR> 0.5 mg/L BR, with weighted total scores increasing by 2.19%, 3.28%, 3.28%, and 1.82%, respectively, compared to the control, particularly in terms of oil content and color intensity; (4) for sensory quality, the order was 1 mg/L BR> 20 mg/L KT> 10 mg/L KT> 0.5 mg/L BR, with weighted total scores increasing by 11.17%, 10.18%, 5.73%, and 0.99%, respectively, compared to the control; (5) in terms of chemical composition, the optimal treatments resulted in nicotine, total sugar, and potassium-to-chlorine ratio within appropriate ranges. KT treatments reduced nicotine content by 3.80%-15.50%, mitigating the strength of upper leaves. In conclusion, applying 20 mg/L KT (to promote leaf expansion) or 1 mg/L BR (to improve quality) on the day of topping is the optimal approaches for high-quality production of upper leaves in Yunnan flue-cured tobacco. This study provides a reference for enhancing the yield and quality of upper leaves in flue-cured tobacco.