The invention provides a tent bottom fixing mechanism comprising a tent rod and a tent base buckle. The tail end of the tent rod is provided with a clamping head. The clamping head comprises a cylindrical body. The outer sides of the middle portion and the bottom of the cylindrical body are both sleeved with cylindrical protrusions. The tent base buckle comprises a clamping plate, a base and a bolt. The clamping plate is hinged to the base. The middle portion of the clamping plate is provided with a clamping through hole. The front end of the clamping plate is provided with a through hole. The back end of the base is provided with a tent fixing hole. The front end of the base is provided with a tent peg hole, and the middle portion of the base is provided with a threaded hole. The bolt penetrates through the through hole to be connected with the threaded hole in a threaded manner. The clamping through hole comprises a U-shaped hole, an arc hole and a rectangular hole. The tent bottom fixing mechanism has the advantages that through the clamping head and the clamping through hole matched with the clamping head, the tent rod and the tent base buckle can be rapidly and stably clamped and fixed, and the phenomenon that after the tent rod is inserted into the tent base buckle, the tent rod may shift up and down is prevented; and the phenomenon that after the tent rod and the tent base buckle are clamped and fixed, the front end of the tent base buckle cocks, a tent peg is convenient to fix, and the tent bottom fixing mechanism is convenient and rapid to use.