The invention discloses an automatic silkworm cocoon hole cutting machine and a hole cutting method, the radial direction of a disk surface of a cocoon separating disk is provided with 2 rectangular slots that are symmetrical along the center of the cocoon separating disk, a horizontal cocoon conveying belt is positioned below the cocoon separating disk, the left end of the cocoon conveying belt is positioned under the cocoon separating disk, the right end of the cocoon conveying belt is tightly connected with the left end of a cocoon conveying passage, a cocoon pushing mechanism is arranged at an upper right position of the cocoon conveying passage, and a photosensitive sensor is installed on the cocoon pushing mechanism; a conveyor belt, an active roller wheel and a passive roller wheel are arranged on the right side of the cocoon conveying passage, a fixture component is fixedly connected on the conveyor belt, a positioning and clamping mechanism is arranged at a conveyor belt position between the active roller wheel and the passive roller wheel, a pushing plate that pushes the fixture to make the fixture open is positioned on the rear side of the positioning and clamping mechanism; a cutting mechanism is arranged at the upper right position of the passive roller wheel, and a cocoon shell separating mechanism is arranged on the left side of the passive roller wheel; batched and automatic hole cutting can be carried out on the silkworm cocoon of different sizes, silkworm chrysalis and cocoon shells can be separated automatically, the positioning is reliable, the cocoon for egg production can not be crushed or injured due to cutting, the cocoon cutting quality is good, and the efficiency is high.