The utility model discloses a self-heat-preserving wall body of a civil building. The heat-preserving wall body comprises an inner brick wall layer, an outer brick wall layer and a lap joint brick layer, wherein the inner brick wall layer is arranged on the side adjacent to the interior of a building, the outer brick wall layer is arranged on the side adjacent to the exterior of the building. The inner brick wall layer, the outer brick wall layer and the lap joint brick layer are composed of multiple inner wall bricks, multiple outer wall bricks and multiple lap joint bricks respectively. The inner wall bricks and the corresponding outer wall bricks are arranged in parallel and the two ends of each inner wall brick and the two ends of each outer wall brick are provided with the lap joint bricks which are arranged to be perpendicular to the inner wall bricks and the outer wall bricks. The inner brick wall layer, the outer brick wall layer and the lap joint brick layer are used for defining an air layer. According to the heat-preserving wall body of the civil building, through the optimized design of a wall body building envelope, the heat preserving performance of an outer wall is improved under the condition that a traditional building block production mode is not changed. Under the condition that heat preserving materials are not adopted, the outer wall heat transfer coefficient requirement in the southern area can also be met. On one hand, the engineering construction cost is saved and on the other hand, the good heat insulating and preserving effect is achieved and the effect of reducing energy consumption of the building is achieved.