A miniature transversely excited atmospheric pressure (TEA)CO2 laser with high output level is reported.The main electrodes of the laser are made of zirconium bronze. The electrodes take the form of Ernst, with bigger space between them, as a result of which the volume of activation area is increased. The spark array preionization makes the discharge even and stable, wiping off the arc. At low repetition rate, the output energy can be as high as 2.5J under the circumstance of free oscillation. Tuning mechanism consists of diffraction grating, trigger controller and high frequency stepping motor of monolithic micro processor control. The energy of multimode of 10P(20) line is 1.2J and the width of the light pulse is 90ns.