The invention provides a joint structure of a tube piece and a tube joint in a shielding interval connecting channel. The joint structure comprises the tube piece and the tube joint, wherein a throughhole is formed in the tube piece, a reinforcing structure is installed on the inner wall of the tube piece, the tube joint penetrates through the through hole, a sealing plate for sealing the gap between the tube joint and the through hole is connected with the side wall of the tube joint, and the sealing plate is fixed to the inner wall of the tube piece. The reinforcing structure comprises a supporting and abutting part for supporting and abutting the sealing plate. The reinforcing structure is arranged on the circumference of the side wall of the sealing plate. By means of the joint structure of the tube piece and the tube joint, the sealing property between the tube piece and the tube joint can be ensured, the good waterproof performance is realized, the connecting strength between the tube piece and the tube joint can be improved, and high safety and reliability are realized.