The invention discloses an inflatable adjustable type construction mold for a reserved hole in a concrete structure plate, and a construction method. The mold comprises a cylinder formed by rolling of a rectangular iron sheet, a circular cover plate for plugging an upper end opening of the cylinder, and an inflatable air bag placed in the cylinder, wherein the cylinder is vertically arranged, and the outer diameter of the cylinder is the same as the hole diameter of the reserved hole needing to be constructed in the concrete structure plate; the inflatable air bag is a cylindrical air bag, and the inflatable air bag and the cylinder are coaxially arranged; and the bottom of the cylinder is supported on a shaping template of the concrete structure plate, the cylinder and the circular cover plate form an outer sleeve, and an outer sleeve fixing piece for fixing the outer sleeve is arranged on the shaping template. The construction method comprises the following steps of I, erecting the shaping template; II, performing measurement and paying-off; III, mounting the mold; IV, casting concrete; and V, dismantling the mold. The inflatable adjustable type construction mold disclosed by the invention is reasonable in design, simple and convenient to mount and dismantle, and good in use effects; after concrete is finally coagulated, the mold is dismantled, so that the quality of the constructed and shaped reserved hole can be effectively guaranteed, and the accuracy of the position of the reserved hole can be guaranteed.