A fireproof structure of a tube joint of an immersed tube tunnel with a linear moving mechanism, comprising a waterproof tape assembly and a fireproof assembly, the waterproof tape assembly and the fireproof assembly being connected between a first tube of the immersed tube tunnel and a second tube of the immersed tube tunnel adjacent to the first tube, the fireproof assembly being spaced from the waterproof tape assembly and positioned at an inner side of the waterproof tape assembly, and the fireproof assembly comprising: a protection plate assembly, comprising a first fireproof plate assembly, a second fireproof plate assembly spaced from the first fireproof plate assembly, and a heat insulation piece fixedly connected between the first fireproof plate assembly and the second fireproof plate assembly; the fireproof assembly further comprising a movable connection assembly, comprising a first movable connection piece fixed to the second tube and abutted against a side of the first fireproof plate assembly remote from the second fireproof plate assembly, and the first movable connection piece comprising a first strip-shaped hole; the movable connection assembly further comprising a first limiting column convexly arranged on a surface of the first fireproof plate assembly facing away from the second fireproof plate assembly and passed through the first strip-shaped hole; one end of the first fireproof plate assembly remote from the second tube being fixedly connected with the first tube; the movable connection assembly further comprising a second movable connection piece, one end of the second fireproof plate assembly being fixedly connected with the first tube, and the other end of the second fireproof plate assembly being movably connected with the second tube through the second movable connection piece; and a flexible fireproof belt positioned between the first fireproof plate assembly and the second fireproof plate assembly, and connecting the heat insulation piece and the second tube. a protection plate assembly, comprising a first fireproof plate assembly, a second fireproof plate assembly spaced from the first fireproof plate assembly, and a heat insulation piece fixedly connected between the first fireproof plate assembly and the second fireproof plate assembly; the fireproof assembly further comprising a movable connection assembly, comprising a first movable connection piece fixed to the second tube and abutted against a side of the first fireproof plate assembly remote from the second fireproof plate assembly, and the first movable connection piece comprising a first strip-shaped hole; the movable connection assembly further comprising a first limiting column convexly arranged on a surface of the first fireproof plate assembly facing away from the second fireproof plate assembly and passed through the first strip-shaped hole; one end of the first fireproof plate assembly remote from the second tube being fixedly connected with the first tube; the movable connection assembly further comprising a second movable connection piece, one end of the second fireproof plate assembly being fixedly connected with the first tube, and the other end of the second fireproof plate assembly being movably connected with the second tube through the second movable connection piece; and a flexible fireproof belt positioned between the first fireproof plate assembly and the second fireproof plate assembly, and connecting the heat insulation piece and the second tube. a movable connection assembly, comprising a first movable connection piece fixed to the second tube and abutted against a side of the first fireproof plate assembly remote from the second fireproof plate assembly, and the first movable connection piece comprising a first strip-shaped hole; the movable connection assembly further comprising a first limiting column convexly arranged on a surface of the first fireproof plate assembly facing away from the second fireproof plate assembly and passed through the first strip-shaped hole; one end of the first fireproof plate assembly remote from the second tube being fixedly connected with the first tube; the movable connection assembly further comprising a second movable connection piece, one end of the second fireproof plate assembly being fixedly connected with the first tube, and the other end of the second fireproof plate assembly being movably connected with the second tube through the second movable connection piece; and a flexible fireproof belt positioned between the first fireproof plate assembly and the second fireproof plate assembly, and connecting the heat insulation piece and the second tube.