As the problem of climate change is becoming more and more prominent, President Xi Jinping has made the important instruction of carbon peak and carbon neutral, so the research on carbon dioxide detection is of great significance. For the need of simultaneous detection of carbon dioxide and water vapor, this paper designs a frequency division multiplexing TDLAS laser drive system. The system adopts STM32H7A3 as the main controller, and uses its internal advanced timer and multi-channel DAC to generate multiple amplitude-frequency-adjustable voltage signals, which are matched with the external V-I conversion circuit and fiber optic combiner to develop the frequency division multiplexing TDLAS laser driving system. The system is equipped with a FLASH memory chip and corresponding host computer software, which has the functions of flexibly setting system parameters, storing and loading control data, and protecting the data from being lost in case of power failure. After testing, the output current signal waveform of the system is stable with low frequency error, which can be applied to TDLAS system to drive multiple lasers at the same time.