A model is proposed for the calculation of the output power of a fast-flow electric-discharge CO//2 laser. The model can be applied to various laser systems (with self-sustaining and non-sustaining discharges, with addition of CO//2 after passing through the discharge zone and without such addition). Quasi-one-dimensional equations of gasdynamics are solved numerically together with equations of vibrational kinetics and allowance is made for the electrical excitation and stimulated transitions. An example of a calculation dealing with a CO//2 plus N//2 plus He laser is given.