利用积分球绝对测量法，对在20 Pa真空缺氧、1 000 Pa空气,105 Pa空气及1 000 Pa氧气环境下，1 064 nm波长连续激光辐照30CrMnSiA碳钢材料过程中的反射光信号进行了测量，得到了30CrMnSiA碳钢在4种辐照环境下的反射率和温度变化曲线。结果表明：在空气组分辐照环境的低压到105 Pa范围内，材料初始反射率随压力增大而增大；在缺氧和富氧环境的激光辐照过程中，缺氧环境下材料反射率变化缓慢，且变化拐点温度高于富氧环境，富氧环境下材料被加热后的快速氧化反应有利于材料对激光能量的吸收;不同辐照环境（缺氧和富氧）相同材料温度条件下，材料反射率并不相同。

The reflectance of 30CrMnSiA carbon steel under laser irradiation in 20 Pa air, 1 000 Pa air, 1 000 Pa oxygen gas and 105 Pa air was obtained by integrating sphere absolute measurement method, and corresponding temperature history curves were got. The results show that the initial reflectance of material in air increases with the pressure varying from 20 Pa to 105 Pa. The change of reflectance is slower and the inflexion temperature of reflectance change is higher in oxygen-deficient environment than those in oxygen-enriched environment. Additionally, in oxygen-enriched environment, the rapid oxidation reaction of material after heating is in favor of laser energy absorption. For given temperature of material, the reflectance of material is different in different irradiation environments.