The invention discloses a negative-pressure automatic sampler of intestinal contents. The sampler comprises a shell, an inlet surface, a contraction neck, inlet holes, a supporting frame, a sealing resin block, sealing film and a protection support. The shell is in a microcapsule shape, one end of the shell is the inlet surface, and a vacuumizing pipe is arranged on one side of the shell. The diameter of the inlet surface is smaller than that of the shell by 2-4 mm, the shell is connected with the inlet surface through the contraction neck, the inlet holes are formed in the inlet surface, andthe supporting frame is arranged on the periphery of the inlet surface. The supporting frame is of a cylindrical frame structure and is fixedly connected with the contraction neck, the sealing resin block is arranged in the supporting frame, and the sealing film is arranged outside the supporting frame. The sealing resin block is in an oblate cylinder shape, the diameter of the sealing resin blockis smaller than that of the supporting frame by 2-4 mm, the height of the sealing resin block is smaller than that of the supporting frame by 2-4 mm, and the sealing resin block is made of water-absorbent resin. The sealing film is in a semispherical housing shape, and the lower circular frame of the supporting frame is sealed by the circular edge of the sealing film. The protection support is arranged on the outer layer of the sealing film, is composed of a circular bottom edge and 3-8 arc supporting rods, and is fixedly connected with the contraction neck. The vacuumizing pipe is hidden inside, is communicated with the inner cavity of the sampler and is sealed after vacuumizing is conducted.