The invention relates to the technical field of knife switches, and especially relates to a safety waterproof knife switch. Mounting plates are disposed on two sides of a housing body; the two sides of the housing body of the lower parts of the mounting plates are provided with inlet wire mechanisms; upper parts of the two mounting plates are respectively provided with a frame body and a mountingblock; a moving block is disposed inside the frame body; a first spring is disposed between one side of the moving block and the frame body; the other end of a cover plate is provided with a positioning block corresponding to a positioning hole; fixed grooves are disposed above the housing body; sealing rings are installed inside the fixed grooves; and the bottom of the interior of the housing body is connected to a knife switch main body through fixation mechanisms. The knife switch is reasonable in design and convenient to operate; the sealing rings are disposed to prevent water from contacting a lead wire part of the knife switch, thereby avoiding the occurrence of a short circuit, and the purpose of protecting the knife switch is achieved; and the knife switch is convenient to dismountthe knife switch main body and replace components, and so, the maintenance time is saved, the maintenance efficiency is improved, thus facilitating using the knife switch by people.