Abstract: In order to study flame propagation regulation after gas explosion accidents in coal mine, a gas explosion experiment system was designed and pipelines with different bend angles were used to simulate underground roadway varying. Relationship between flame propagation velocity in pipelines and pipeline bend angle or gas filling length was researched by experimental method. The experimental results show that the longer gas filling length is, the larger flame propagation velocity is; flame propagation velocity increases in horizontal section, quickly decreases at bend point and increases after bend point; with the same gas filling length, the larger turning angle is, the larger flame propagation velocity is; flame propagation velocity varying coefficient decreases firstly and then increases with pipeline bend angle increases, and gas filling length has no significant influence on the flame propagation velocity varying coefficient.