To investigate the effects of chitooligosaccharide foliar fertilizer on soybean yield and quality，a study was conducted using the high-oil soybean variety “Kennong 23” as experimental material. The effects of foliar spraying with water(CK)，chitooligosaccharide.(T1)，chitooligosaccharide + chelated iron(T2)，chitooligosaccharide+organic silicon(T3)，chitooligosaccharide + organic calcium(T4) and chitooligosaccharide + chelated iron + organic silicon + organic calcium(T5) during the pod-filling stage on soybean leaf photosynthetic parameters，dry matter accumulation，yield，and quality were analyzed. Results showed that chitooligosaccharide foliar fertilizer treatments significantly increased leaf net photosynthetic rate and dry matter accumulation. Soybean yield and net profit increased by 6.83%-14.31% and 5.73%-19.04%，respectively，compared to CK. All treatments significantly enhanced yield in the upper parts of soybean plants but had no significant effects on middle and lower parts，compared to CK. Different treatments variably influenced yield components:T1，T3，T4 and T5 treatments significantly increased grains per pod and 100-seed weight，while T2 treatment significantly improved pods per plant and 100-seed weight. Crude protein content in grains followed the order upper > middle > lower parts，whereas crude fat content exhibited the opposite trend. At maturity，chitooligosaccharide foliar fertilizer treatments increased crude protein content by 9.16%-13.46% and reduced crude fat content by 2.07%-6.10%，compared to CK. Thus，chitooligosaccharide foliar fertilizer effectively enhanced drip-irrigated soybean yield，with the chitooligosaccharide + chelated iron combination demonstrating the most significant yield and economic benefits.