A rapidly tunable TEA CO2 laser is reported. The main electrodes of the laser take the form of Ernst with the spark array preionization. With the method of a two-dimensional (2D) scanning system and a diffraction grating, rapidly tuned TEA CO2 laser output is realized. Laser with 75 emission lines of the CO2 molecule rotational transition is obtained, and there are 55 lines, whose pulse energy of laser radiation exceeds 1 J. The pulse energy of 10P(20) line is over 300 mJ in single-transverse mode at a repetition rate of 100 Hz, and the width of the light pulse is 70 ns. The system can be tuned between two different rotation lines spanning the wavelength range from 9.2 to 10.8 μm within 10 ms.