The invention provides a low-dome lamp shell and a low-dome lamp, and belongs to the field of lighting lamps. The low-dome lamp comprises a shell and a light emitting element arranged in the shell. The shell comprises a first shell and a second shell, wherein the first shell comprises a panel and an outer cylinder, and the panel is connected to one end of the outer cylinder; the panel comprises alight-transmitting area; the second shell is arranged in the outer cylinder, and the second shell comprises a connecting flange and an inner cylinder; one end of the inner cylinder is closed, the other end of the inner cylinder is connected with the connecting flange; and the connecting flange is matched with the inner surface of the panel and seals the space between the connecting panel and theinner cylinder to form an accommodating space, wherein the accommodating space can accommodate the light-emitting element. Since the connecting flange of the second shell is in sealing connection withthe inner surface of the panel of the first shell, a closed accommodating space is formed, and an electronic component is sealed in the accommodating space; and therefore, the electronic component ofthe whole low-dome lamp can be isolated from the outside moisture, so that the waterproof performance of the low-dome lamp is improved.