The invention discloses a keyboard dust-proof cover. The keyboard dust-proof cover is transparent. The keyboard dust-proof cover is of an arch-bridge structure with a bridge opening. The keyboard dust-proof cover is vertically arranged on the keyboard. A protecting bag is connected with the bridge opening portion. A hand entrance communicated with the bridge opening is formed in the protecting bag. The keyboard dust-proof cover can effectively prevent some dust, impurities and other tiny objects from falling in gaps of a keyboard no matter whether the keyboard is used or not, and therefore the defects that device environmental hygiene is influenced, a device fault is possibly caused, and device normal use is influenced are avoided and overcome.