The utility model discloses a telescopic necking well lid in the field of well lids. The well lid is formed by a well hole lid and at least one annular sleeve lid which is arranged at the outer side of the well hole lid, connected with the well hole lid in a sleeved mode and is supported. Due to the adoption of the structure and especially the arrangement of the annular sleeve lids, the diameter of a well hole is effectively reduced, the bearing capacity of the well lid is strengthened obviously, the number of the annular sleeve lids can be designed according to the diameter of the well hole and the requirements of users to meet actual needs, and flexibility of use is increased. The telescopic necking well lid further has the advantages of being simple and novel in structure, scientific and reasonable in design, convenient and flexible to use, and suitable for popularization.