The typical roof tiles made from soil or clay will be limited because it destroyed the farmland. On the other hand, the old tire and waste plastic increase year and year, which bring a serious environmental problem. So the roof tiles made from old tire and waste plastic will help a lot to decrease above environmental pressure. To get a suitable formula of roof tiles made from waste rubber tire powder and waste plastic, the present article studied mechanical performance of a series of composites. Then a preferred formula was got through comparing the mechanical performance.