The utility model discloses a novel inclined column pitched roof extension board-pile composite foundation, and relates to the technical field of high voltage transmission lines. The novel inclined column pitched roof extension board-pile composite foundation consists of a composite foundation which is divided into two parts, the upper part refers to an inclined column extension board foundation, and the lower part refers to a cast-in-situ bored pile foundation. The composite foundation is formed in a way that a reinforcing cage formed by main bars and reinforcing steel bars in the inclined column extension board foundation at the upper part and main bars in the cast-in-situ bored pile foundation at the lower part are banded or welded into a whole, and are then subjected to concrete placement. The novel inclined column pitched roof extension board-pile composite foundation is divided into two parts, the requirements on the bearing capacity of two soil bodies at a flood land area can be fully met by means of the combination of the board foundation at the upper part and the pile foundation at the lower part, rain water can be prevented from accumulating on the top face of the foundation, corrosion to the steelwork by rain water can be reduced, and the strength degradation of foundation anchor bolts caused by fire bending processing can also be avoided.