The invention discloses a water, moisture and corrosion preventing electric control box, which comprises a box body, a box door covered at the front of the box body, a radiator arranged at the back of the box body, and an electric control component installed in the box body, and is characterized in that the bottom part of the box body is provided with a wire inlet and a wire outlet, the wire inlet and the wire outlet are internally provided with a waterproof joint; the outer periphery of the front end of the box body is provided with a water release slot in a concave mode, and the bottom part of the box door is provided with water release holes corresponding to the water release slot; a waterproof sealing strip is installed between the front end of the box body and the box door; the radiator is fixed at the back of the box body, the periphery of an installation surface of the radiator is provided with a plurality of grooves, the grooves are internally provided with waterproof slow drying flexible glue, and a joint surface of the radiator and the back of the box body is sealed by the waterproof slow drying flexible glue. Because of the multiple waterproof measures, water does not get into the box body even in a raining environment outdoor, thereby effectively preventing water, moisture and corrosion, and being particularly applicable to field operation environments such as offshore platforms, mines, pits and the like.