A voice coil motor strongly attached to the base of a camera module comprises the base and a casing. The casing and the base are interlocked with each other. The casing is a hollow structure. The casing comprises a top surface and a side wall surrounding the top surface. The side wall and the base are engaged with each other. The side wall is extended in parts to form at least one extending leg. The extending leg extends to a side of the base away from the top surface and is bent toward the base.