The utility model provides a clearance formula preforming machine quick detach formula steam gas permeable plate, a plurality of stainless steel steam gas permeable plate fix on the fan -shaped aluminium alloy plate of a plurality of pieces, and the fan -shaped aluminium alloy plate of a plurality of pieces makes up into aluminum alloy air chamber board to install on the air chamber of preformingmachine bottom, it compresses tightly aluminum alloy air chamber board to open clamping ring to be equipped with one in the middle of the air chamber. The utility model discloses change original gas permeable plate's mounting means and structure, solved the deformation of air chamber board expend with heat and contract with cold and leaded to the not hard up problem of screw fracture, improved thereliable degree of part, guaranteed that the air chamber bottom plate levels, reduced the production of lump material when sending out the material, reduced the intensity of labour that operator in the cleaning process was dismantled to the air chamber board.