The invention discloses a cast wheel cavity exhaust device which comprises a bottom die (1), an edge die (2), a top die (3), an upper exhaust pin (4) and a lower exhaust pin (5). A boss (11) is arranged on the portion, corresponding to the window modeling portion of a wheel, of the bottom die, a groove cavity (31) is formed in the portion, corresponding to the boss, of the top die, the boss (11) of the bottom die is provided with a step hole, and the lower exhaust pin (5) is installed in the step hole. The top die and the bottom die are provided with an exhaust groove and exhaust pin dual structure, active exhaust of a die cavity is achieved, gas circulation smoothness is improved, a gas blocking area is eliminated, the defects of oxide inclusion, air holes, needle holes and the like likely to occur on castings are overcome, the finished product ratio is greatly improved, and high-quality production of wheels is ensured.