There is physical processing of laser energy absorption and attenuation in coaxial powder flow. Theoretical models of temperature fields for carrying gas/powder two phase flow from coaxial nozzle have been presented from Beer-Lambert law. Based on the models, the calculated simulation of temperature field in powder flow has been achieved. The influences of laser cladding parameters, such as laser power, powder mass flow rate and gas flow volume, on temperature distribution have been discussed. Temperature field in powder flow has been measured by CCD camera. It is shown from both simulated and experimental results that temperature in centre axial line of powder flow will be significantly increased from outlet of nozzle to part surface. It is available to laser cladding.