Combined mullite top cover brick

The utility model discloses a combined mullite top cover brick which comprises a brick body, an upper positioning rod and a lower positioning rod are respectively fixed at the upper end and the lower end of one side outside the brick body, and an upper slot and a lower slot are respectively arranged at the upper end and the lower end of the inner wall of one side, far away from the upper positioning rod and the lower positioning rod, of the brick body; a left positioning block and a right positioning block are fixed to the two sides of the front portion of the brick body respectively. According to the utility model, the upper positioning rod and the lower positioning rod of one brick body are respectively inserted into the upper slot and the lower slot of the other brick body, so that the two brick bodies can be transversely combined; the left positioning block and the right positioning block of one brick body are respectively inserted into the left positioning groove and the right positioning groove of the o