A high average power TEA CO2 laser has been developed.Average output power of 3.3 kW is achieved at a repetition of 150 Hz.The TEA CO2 laser consists of two same laser modules,each of which has a 5 cm×4 cm×90 cm discharge volume.Several special technologies including Printed Circuit Board（PCB） pre-ionization and thyratron switch discharging circuit are employed.The laser realized large energy output,high repetition operating and high average power output.Laser output pulse energy is measured.The relationship between laser pulse energy and voltage at different gas pressures is obtained.The maximum of output pulse energy is 32.8 J.Electro-optical efficiency is calculated and the maximum of electro-optical efficiency is 15.4%.The laser pulse waveforms are measured at different gas pressures.