As an important link in carbon emission reduction in the steel industry， the production process of lime kiln is mainly air-fueled combustion， and the CO₂ concentration in the exhaust gas is low，making it difficult to achieve low-cost carbon capture. Oxygen-enriched combustion is an effective carbon enrichment technology，but the high volume fraction CO₂ gas radiation in the lime kiln will affect the temperature distribution and decomposition characteristics of calcium carbonate in the kiln. Therefore， the double-chamber lime kiln is taken as the research object to establish a numerical simulation model of the lime kiln production process，study the effect of gas radiation on the calcination characteristics of limestone under oxygen-rich combustion，and compare the changes of temperature，composition and calcium carbonate content in the kiln under different O₂/CO₂ ratios. The results show that the CO₂ component concentration in the lime kiln does not change significantly after considering the gas radiation，but the maximum temperature in the kiln decreases by about 60～ 100 K，and the maximum gas phase temperature increases with the increase of O₂ volume fraction. After considering the gas radiation，the average temperature of the gas phase and calcium carbonate in the calcination area in the lime kiln is increased，and the decomposition rate of calcium carbonate in the kiln is increased，and the average temperature of the gas phase is increased by about 30～90 K，and the average temperature of calcium carbonate is increased by about 30～130 K increasing with the increase of O₂ volume fraction，and the decomposition rate of calcium carbonate in the kiln also is accelerated with the increase of O₂ volume fraction. The results can provide theoretical support for the accurate simulation of temperature and calcium carbonate decomposition characteristics in lime kilns，and also provide a reference for the application of oxygen-rich combustion technology in double-chamber lime kilns.