The present invention provides a shell for a lighting device. The shell comprises a first lamp body, a second lamp body, a first connecting part, and a second connecting part. The ends of the second lamp body have a first end surface and a second end surface. The first connecting part lying along a first direction is set in the first end surface and threads through the first bottom surface. The second connecting part lying along a direction opposite to the first direction is set in the second end surface and threads through the second bottom surface. When the first lamp body is connected with the second lamp body, the two ends of the first lamp body are disposed extending over edges of the first end surface and the second end surface separately.