The invention discloses a furnace hood and a rotary hearth furnace. A working surface of a top wall of the furnace hood is of a concave structure, and included angles between the working surfaces of two side walls and a furnace bottom are set to be smaller than 90 degrees, so that the top wall and the side walls can be used for carrying out thermal radiation on materials inside a hearth respectively by different angles in different oblique downward directions, and thus, the area of the materials for receiving the thermal radiation is increased. In addition, because heat of the side walls of the furnace hood is transferred downwards obliquely, the thermal radiation can be carried out on the materials directly, and thus, loss caused when the heat is transferred in the horizontal direction is reduced and the utilization ratio of the heat is increased.