In-situ detection system and method for harmful gas dissolved in tunnel drilling

The invention provides an in-situ detection system and method for harmful gas dissolved in tunnel drilling, and relates to the technical field of concentration detection of methane dissolved in drilling, and the in-situ detection system comprises a set construction module which is used for selecting a road section with the length of L meters in a tunnel, setting the road section as a methane concentration detection area, numbering drilling holes in the detection area according to a sequence to form a set A, marking the detected methane concentration test value corresponding to each drill hole in the set A, and forming a test value set B; the data acquisition module is used for acquiring environmental influence parameters of the methane concentration in each drilling water in the set A and detection equipment influence parameters, and the environmental influence parameters comprise a temperature coefficient and a water pressure coefficient. According to the invention, a plurality of modules are matched to acqu