Abstract: Rice lodging is an important factor affecting yield and quality, and the rational use of plant growth regulators is an effective measure to prevent rice lodging. To explore the application effectiveness of new plant growth regulators, the effects of 15% prohexadione calcium + uniconazole (PCU) water dispersible granule (WG) on rice plant morphology, lodging resistance, and yield were studied using rice varieties ‘Huangjinqing’ and ‘Xinfeng2’ as test materials in 2021-2022. A split zone experimental design was adopted, with the variety as the main zone, the application period as the split zone, the plant growth regulator treatment as the split-split zone, and the water treatment (CK) and 15% paclobutrazol wettable powder treatment as controls. The results showed that foliar application of 15% PCU WG at the tillering and jointing stages of rice significantly altered plant architecture: it reduced plant height by 4.6%-11.5%, center of gravity height by 5.5%-12.0%, and basal internode length by 2.9%-83.3%, while increasing stem thickness and internode wall thickness, thereby improving lodging resistance. Among those treatments, the greatest yield increase was achieved by spraying 90 g/hm² of 15% PCU WG at the jointing stage. By increasing the number of spikes per unit area, thousand grain weight, and seed setting rate, the yields of ‘Huangjinqing’ and ‘Xinfeng2’ were increased by 10.6% and 7.7%, respectively. The research results provide technical support for the scientific use of 15% PCU WG in rice production, which has important application value in preventing rice lodging and improving yield.