A driving generator to drive multiple infrared Quantum Cascade Lasers (QCLs) was designed under an experimental validation for detection of mixed infrared gases. To avoid the cross-influence of the driving currents among multi-channels, the Time Division Multiplexing (TDM) method integrating with the fast analog proportional-integral (PI) control theory was used to adjust the regulating output currents in each branch independently. A control method combined pulse frequency modulation (PFM) and Pulse Width Modulation (PWM) was proposed to improve the characteristics of the operating frequency and the pulse width of driving pulse and to guarantee the lasers of each branch to operate in an optimum condition. By utilizing the illustrated driver, a driving test was performed on four QCLs with center wavelengths at 4.8, 7.49, 7.71 and 10.7 μm respectively fabricated by Institute of Semiconductor, Chinese Academy of Sciences. Experimental results demonstrate that the stability of driving current is 4.62×10-6 and the linearity of power system is 0.029 1% during a long-term operation (220 h), which meets the requirements of driving multiple QCLs and provides a strong guarantee for mixed infrared gas detection.