为了获得大功率CO2激光功率分布的解析表达式，采用热敏纸测量大功率CO2激光器在不同功率和高度时的激光功率分布，用MATLAB软件对实验光斑进行图像处理，建立了数学模型模拟激光功率分布，并与采集光斑进行了比较。通过激光热处理实验及温度场计算验证激光功率分布模型，取得的实验结果和理论计算相符合。结果表明，采用热敏纸测量大功率CO2激光功率分布的方法是可行的。得到的功率分布的解析表达式可作为理论计算的条件，具有一定意义。

In order to obtain the analytic expression for CO2 laser power distribution, the power distribution of a CO2 laser was measured with thermal paper at the different heights and output power. The experiment images of the laser spot were processed with MATLAB, and a numerical model of laser power distribution was built up and compared with the experimental spot. The obtained analytic expression was verified with the measurement results in laser heat treatment experiments and calculation results of temperature field. The experimental results were in good agreement with the theoretical calculation. The results show that it is feasible to measure the laser power distribution with thermal paper, and it is practical to calculate the power distribution based on the analytic expressions.