The invention discloses a demonstrator shell and a robot demonstrator, comprising a first shell, an annular sealing seat is arranged in the first shell, and a sealing groove is arranged on the end face of the sealing seat; an inner sealing ring arranged in the sealing groove; a second shell arranged on the first shell, the second shell and the first shell forming a cavity, and an annular fin corresponding to the sealing seat being arranged in the second shell, and the fin being pressed on the inner sealing ring, so that the sealing ring is lower than or equal to the end face of the sealing seat; the fins and the sealing seat separating the cavity into a receiving cavity and a water retaining cavity. Since the inner sealing ring is installed in the sealing groove of the sealing seat, when the second shell is installed on the first shell, the torsional bending of the inner sealing ring does not occur, and the assembly does not need to be carefully adjusted for many times, so that the installation process of the first shell and the second shell becomes simple; and in addition, even if the external water enters the water retaining cavity, it will be resisted by the sealing seat or finsfirst, and then blocked by the inner sealing ring, thereby achieving a relatively high level of sealing.