In the process of natural gas transmission and oil extraction, in order to ensure the safety of personnel and equipment need to accurately detect CH₄ gas concentration, based on the TDLAS laser gas detection technology designed a data acquisition system capable of high-precision measurements of CH₄ gas concentration, the system selects the STM32H743 as the main control chip, adopts the ADC's dual mode, utilizes the internal ADC1 collects the fundamental and second harmonic signals, and the internal ADC2 collects the temperature and pressure data of the gas, and then the data are averaged, and the averaged calculation parameters are controlled by the master chip, and the data are transmitted and stored through DMA, and finally the master chip integrates and processes the multiple sets of data and sends them to the upper computer through the virtual USB interface in accordance with the specified data protocol. After actual testing, the system can collect and process data in a high-speed and stable way, and can be applied to other gas TDLAS detection systems.