Falling-free constant-pressure opening sealing device

The utility model discloses a falling-off-free constant-pressure opening sealing device, and relates to the field of sealing and constant-pressure opening of pipelines. The constant-pressure opening and sealing device comprises an outer frame, the cover body is connected with the pipe wall through the outer frame and comprises a first anti-falling layer and a first sealing layer, the first anti-falling layer is wrapped with the first sealing layer, at least one stress groove is formed in the first sealing layer, the cover body is divided into a first area and a second area, the position where the stress groove is formed is the first area, and the rest is the second area; the first anti-falling layer is arranged in the second area. When the stress groove is broken, pressure relief is carried out, the first anti-falling layer is arranged at the position where the stress groove is not formed, and therefore the first anti-falling layer can generate tensile resistance on the two sides of the stress groove, and the