Abstract: This study is based on a 60-day simulated culture experiment of sediment from municipal drainage pipes. Gas chromatography and three-dimensional fluorescence spectrum were used to analyze the response of CO2 production and emission fluxes and dissolved organic matter (DOM) degradation processes of sediments in different types of pipes (sewage pipes, rainwater pipes, rainwater, and sewage mixed pipes) to hydraulic conditions (i.e., simulated continuous flow condition, cut off flow condition, intermittent flow condition and discharge condition of pumping station). The main conclusions are as follows: Under the first three simulated working conditions, the sediments of the rain-sewage mixed pipeline showed the highest cumulative CO₂ emission fluxes, which were 2.36×10⁵ mg· m², 1.95×10⁵ mg· m² and 2.03×10⁵ mg· m², respectively. The cumulative CO₂ emission flux of sewage pipe sediments reached the highest level (2.23×10⁵ mg·m²). Compared with the cut-off condition, the CO₂ production and emission flux decreased significantly due to the continuous loss of endogenous sources, while the CO₂ production and emission flux increased slightly due to the large amount of gas storage in the sediment gap at the initial stage of drainage. There was no significant difference in the initial DOM components of the three types of pipeline sediments, mainly tryptophan (ex/em 275/340 nm) and anthropogenic humus (ex/em 260/400~425 nm). Sewage carbon is a necessary condition for the stable production and discharge of CO₂ in sediments and also an important factor for shaping the DOM degradation potential energy (DP) of sediments. Extracellular polymers (EPS) are closely related to CO₂ production and emission, and ammonia nitrogen may be an essential factor affecting the CO₂ production and emission under continuous flow and cut-off conditions, while TN and COD may be the main factors affecting CO₂ production and emission under intermittent flow and drainage conditions, respectively.