Abstract: The hundred-watt transverse-flow CO2 laser is designed.The laser utilized the technique of gas transverse flow and longitudinal confined discharge to obtain the maximum discharge area and the uniform discharge property.V-A characteristic of the laser has been detected,and the V-A curve is a slow variation.In our system,the maximum discharge power is high up to 2440W,the quantum efficiency is 40%,the electron-photo transfer efficiency is 10%～20%.