Abstract: To improve the quality of syngas and further promote the wide application of biomass gasification technology in industries such as energy and chemical engineering, this study used corn straw (a typical agricultural biomass resource) as the raw material, quartz sand as the bed material, and conducted oxygen-enriched directional gasification experiments with a self-heating bubbling fluidized bed as the reaction device. Taking the hydrogen-carbon ratio (H/C) as the target parameter, the study systematically investigated the effects of equivalence ratio (ER) and oxygen concentration (OC) on the concentrations of hydrogen (H₂) and carbon monoxide (CO) in the syngas, as well as the hydrogen-carbon ratio (H/C) itself. The experimental results showed that on the premise of achieving the optimal H/C ratio, the concentration of H₂ in the syngas increased gradually with the gradual increase of both ER and OC. The experiment found that increasing OC to 100% and raising ER to the range of 0.36~0.39 (high ER range) facilitated obtaining a relatively high H₂ concentration, which reached a maximum of 23.1%. The concentration of CO was regulated by the interaction between ER and OC. At low OC levels (30%~35%), the CO concentration had a positive correlation with ER; this was because when OC was low, a proper increase in ER promoted the combustion of combustible components in the gasifier and released more heat, while the rise in gasification temperature was conducive to enhancing reactions such as the Boudouard reaction. At high OC levels (>50%), the CO concentration showed a negative correlation with ER; this was because when OC was high, increasing ER led to excessive oxygen in the gasifier, and part of the CO generated from gasification reactions was oxidized to CO₂. In addition, under different ER conditions, increasing OC was generally conducive to improving the CO concentration in the syngas. The experiment also found that on the premise of achieving the optimal H/C ratio, increasing OC to 100% and setting ER to the range of 0.28~0.30 (medium ER range) helped obtain a relatively high CO concentration, with the maximum reaching 41.54%. The H/C ratio could also be regulated by ER and OC. When OC was low (30%~35%), increasing ER had a small impact on the increase of H/C ratio; when OC was higher than 50%, increasing ER was more beneficial to enhancing the H/C ratio. Besides, under different ER conditions, an OC close to 75% was favorable for obtaining a relatively high H/C ratio. Specifically, when OC was set at 75.1% and ER at 0.39, a relatively high H/C ratio was achieved, reaching a maximum of 0.66. However, when OC was further increased to 100%, the pure oxygen condition promoted the preferential oxidation reaction of carbon, generating CO₂ and CO, while the water-gas reaction was relatively weakened. As a result, the increase rate of CO concentration was relatively significant, while the increase rate of H₂ concentration was relatively weakened, which led to a slight decrease in H/C ratio.The results of this study could provide solid theoretical support for the application of oxygen-enriched gasification technology in bubbling fluidized beds in the industrial field.