A tunable TEA CO₂ laser with tubulous preionizer is developed.With optical bridge and folded cavity,laser is compact and stable.Tunable laser output is realized by grating resonator.73 lines of the CO₂ molecule rotational transition which wavelengths range from 9.19 to 10.86 μm are obtained,and there are 45 lines whose pulse energies of laser radiation exceed 2 J.The maximum pulse energies of P10(20),R10(20),P9(20),R9(20) are 5.3,5.4,5.5 and 5.1 J with the corresponding electro-optical efficiency of 9.6%,9.8%,10.0%,9.3%;The maximal electro-optical efficiency of the above four lines are 10.3%,10.7%,10.7% and 10.7% respectively.Under the gas pressure of 30 kPa,the maximal specific injection energy is 2.626 J/(L·kPa),and the maximal specific output energy of P9(20) is 0.205 J/(L·kPa).Laser pulse waveforms of the above four lines with different gas pressures are measured;The output pulse widths vary from each other,and the width of R9(20) is the largest.The far-field divergence angle is 2.6 mrad.Tunable high repetition laser output is realized at the repetition rate of 190 Hz.