This study, combined with the advantages of both nondynamic degasser and dynamic degasser, developed a smallsized centrifugal splash degasser characterized by low flow amount and low flow velocity, and thus established a set of fast monitoring system which can be used for monitoring drilling gas of continental gas hydrate. In this system, gases is collected automatically from drilling mud in a degassing tube, inlet into field laboratory using tubes, and analyzed with the gas chromatographic analyzing system. This system can analyze a wide range of gases, such as CH4, C2H6, C2H4, C3H8, C3H6, nC4H10, iC4H10, nC5H12, iC5H12, O2, N2, CO2 and CO. Among them, the low limits for hydrocarbon gases and nonhydrocarbon gases are 01 to 100 μL/L and 100 μL/L to 001 %, respectively. The gas monitoring precision is lower than 116 with the detection limits ranging between 010~100 μL/L, and an analysis cycle of about 10 minutes. This rapid gas monitoring system has passed through the trial run in Well MK2 for Scientific Drilling and Exploration of Gas Hydrates in the Mohe permafrost, thus realizing the live fast monitoring for drilling gas. The results show that this system is sensitive, stable and reliable, and is of better precision and low detection limit. Therefore, this system can basically meet the requirement of onsite monitoring.