A kind of shell structure of flow sensor,Including one first pipe fitting and one second pipe fitting； First pipe fitting has one first detection channel,First detection channel is directly connected to one first extension； Second pipe fitting has one second detection channel,Second detection channel connects one second extension； The wherein side of first extension and the second extension position what second pipe fitting,First detection channel is connect in line with first extension； When second pipe fitting sealing combines first pipe fitting,Second detection channel can be connected to second extension.一種流量感測器的殼體結構，包括一第一管件及一第二管件；該第一管件具有一第一偵測通道，該第一偵測通道直接連通一第一延伸管；該第二管件具有一第二偵測通道，該第二偵測通道連接一第二延伸管；其中該第一延伸管與該第二延伸管位於該第二管件的一側，該第一偵測通道與該第一延伸管連接成一直線；該第二管件密封結合該第一管件時，該第二偵測通道可連通該第二延伸管。
