To provide a cylinder body connection structure which mechanically connects cylinder bodies to each other without welding, and to provide a method of connecting the cylinder bodies.

The cylinder body connecting structure T is formed of: a first repelling member 6 which is arranged in the first cylinder body 1, and energizes heads 41 of a plurality of first cylinder body bolts 4 to the outside of the first cylinder body 1; and a second repelling member 10 which is arranged in the second cylinder body 2, and energizes heads 81 of a plurality of second cylinder bolts 8 to the outside of the second cylinder body 2, and functions to connect the first and second cylinder bodies together via a joint 3 by means of the bolts 4, 8 and nuts 5, 9.