The utility model discloses a floating roof tank and manhole barrel strutting arrangement thereof, strutting arrangement include that parallel manhole barrel sets up the supporting cylindrical in the manhole barrel and the apron of the internal wall shape of corresponding floating roof tank jar setting, supporting cylindrical includes the orientation the first end of jar internal wall and keeping away from the second end of the internal wall of jar, the apron seals the first of supporting cylindrical is served, will manhole barrel intercommunication the internal opening of jar covers. The utility model is used for mend the breach of total man hole barrel department for the adherence capsule is fully supported in here, can not produce and pull the deformation, has eliminated the capsule and has pullled the damage risk, reaches the purpose of long -term reliability service.