In carring gas/powder two phases flow from laser coaxial nozzle there are three main physical processings of energy, momentum and mass transferences, which directly affect the quality and accuracy of the parts by laser manufacturing. Comprehensive results reseached on momentum and mass transferences of the two phases flow have been reported: Physical model of the two phases flow from laser coaxial noozel is presented. A set of governing equations of mass and momentum conversation for each phase are established based on Euler theory for two-phase flow. FLUENT 6.0 software is developed to solve the momentum equation and continuity equations. DPIV (Digital Particle Image Velocimetry)with special image processing software is developed to measure concentration and velocity fields in the gas/powder stream. It is shown that there are good identical results between numerical simulation and DPIV measurement.