The invention relates to a method for testing capacity of permeating water vapor of dressing. A dressing container is arranged as a capacity wound model for the dressing capable of permeating water vapor; a transparent shell is arranged on the capacity wound model for the dressing capable of permeating water vapor; a cover is arranged on the transparent shell; a slot, a sponge slot and a through hole are formed on the middle part of the cover in turn; the slot and the sponge slot are communicated with the through hole; the through hole is communicated with a liquid storage chamber of the transparent shell; a needle hole is formed on a side wall of the cover; the needle hole is connected with the sponge slot. Due to the design for the capacity wound model for the dressing capable of permeating water vapor, the quantity of the liquid absorbed by the dressing can be simultaneously tested, so that the medical liquid controllability for different dressings can be correctly selected.