利用双光束反射率测量装置，研究了连续激光重复加载作用下30CrMnSiA钢金属材料的反射率变化特性。通过激光加载、冷却然后再加载到更高的温度的辐照试验与激光单次辐照的结果比较，发现二次加载时材料表面的激光反射率与样品表面首次加载时达到的最高温度所对应的反射率基本一致，只有达到并超过首次加载时样品曾达到的最高温度后，样品表面的反射率才会再次发生变化，且变化趋势与单次完整加载时的路径重合。这表明样品表面的反射率与其达到的最高温度有关，进一步的研究结果表明，样品达到的最高温度与样品表面在最高温度下产生的氧化反应层有关，而这一氧化层在冷却过程和再加载过程不变化。

The reflectivity characteristic of 30CrMnSiA steel under continuous-wave laser repeated irradiation is explored,by using the double-beam reflectivity measurement device.The reflectivity under only once laser irradiation is compared with that in the process of laser irradiation,cooling,laser re-irradiation.It is found that the reflectivity under the laser re-irradiation is basically the same with the reflectivity corresponding to the maximum temperature in the process of the first laser irradiation, and begins to change only when the temperature exceeds the maximum temperature, and the variation trend of the reflectivity under the laser re-irradiation is the same with that under only once laser irradiation. It indicates that the reflectivity on the surface is related to the maximum surface temperature.The further study results show that the maximum surface temperature could affect the surface oxide layer and the oxide layer thickness does not change in the cooling and re-irradiation process.