A transversely excited (TE) CO2 laser with special gas flow scheme and auxiliary discharge configuration has been designed. In this laser, mixed gas was forced to flow through a structure of square tubes with meshes on both sides. An array of auxiliary electrodes was added to ensure uniformity of the main discharge. By introducing these structures, an output power exceeding 3000 W/m was obtained. The system could be operated continously over 15 hours under sealed condition. The contours of constant gain distribution along the direction of gas flow were drawn.