Abstract: Spring drought in Yunnan frequently coincides with the flowering stage of coffee, yet its combined impact on floral development and bean quality remains unclear. Using two-year-old coffea plants, we imposed four irrigation regimes during anthesis: light drought (LD, 55–60% of field capacity), moderate drought (MD, 40%–45%), severe drought (SD, 25%–30%), and a well-watered control (CK, 75%–80%). Compared with CK, LD caused no significant changes in the numbers of flowers and fruits or in yield per plant. In contrast, MD and SD markedly inhibited growth: SD reduced floral bud and open-flower counts by 50% and 44%, respectively. Both MD and SD decreased fresh-fruit and green-bean transverse and longitudinal diameters, hundred-seed weight, fresh-to-dry weight ratio, and overall yield, and they altered the chemical composition of green beans. Collectively, the data indicate that maintaining soil moisture at ≥55% of field capacity during flowering avoids yield and quality losses. We therefore recommend this threshold as a practical irrigation standard for coffee cultivation in regions subject to spring drought.