With China's urbanization advancing, the annual volume of municipal solid waste (MSW)collection continues to rise. MSW gasification has gained significant attention due to its largeprocessing capacity, economic benefits, and low pollutant emissions. This study systematicallyEnergy Environmental Protectioninvestigates the effects of reaction temperature and equivalence ratio (ER) on MSW gasification using afixed-bed reactor, focusing on syngas composition, tar formation characteristics, and slagging behaviorof gasification ash. Additionally, the transformation of tar compounds and the fusion properties ofgasification ash under varying conditions are explored. Experimental results show that increasing thegasification temperature enhances MSW decomposition and tar cracking, leading to higher syngas yieldand calorific value. As ER increases from 0 to 0.3, tar conversion into oxygenated compounds such asaldehydes, ketones, and acids is promoted, significantly improving syngas calorific value. However,when ER exceeds 0.3, excessive oxidation of CO and H reduces syngas quality and calorific value. Atan optimal temperature of 700 ℃ and ER of 0.3, the highest syngas calorific value of about 23.51MJ/Nm is achieved, with increased gas yield and reduced tar formation. X-ray fluorescence (XRF)spectroscopy and ash fusion analysis indicate that MSW gasification ash primarily consists of SiO,AlO, and CaO. As ER increases, the hemispherical temperature (THT) and flow temperature (TFT) ofthe ash rise, suggesting a decrease in slagging propensity. However, slagging tendency calculationsindicate a significant tendency for slagging under various conditions, posing potential risks to long-termgasifier operation. This issue is attributed to the high content of alkali metal oxides (such as FeO andKO) in the gasification ash. These oxides react with SiO and AlO to form low-melting eutecticcompounds, reducing ash viscosity and increasing adhesion, thus exacerbating slagging at hightemperatures. The study further highlights that gasification ash composition is highly sensitive tooperating conditions. Slagging issues can be mitigated by adjusting the MSW feedstock composition orby adding SiO and AlO as additives to improve reactor stability. Additionally, while increasing ERpromotes syngas yield by facilitating tar cracking, excessive ER leads to undesirable oxidation ofvaluable syngas components, resulting in a trade-off between syngas production and calorific value. Insummary, reaction temperature and ER play crucial roles in determining MSW gasification efficiencyand stability. Proper optimization of these parameters enhances syngas quality while reducing tarformation and slagging risks. The findings of this study provide theoretical support for the industrialapplication of MSW gasification technology and offer new insights into optimizing syngas composition,improving ash behavior, and advancing sustainable waste-to-energy conversion.