An air-permeable simple car cover tent is formed by covering a cover onto a plurality of supports and a base. One end of the cover is provided with a falling part, two holes, and at least an air window. The top of the falling part is connected with the cover. The base is provided with a first and a second lateral plate that are parallel to each other and connected to the bottoms of a first and a second support legs and each support, so that each support is movable on the base. The tops of the first and the second support legs are inserted into the holes of the cover and connected to the bottom of the falling part to prop the falling part open and air can flow through the cover.