Well lid supporting device and sewer well

The utility model provides a well lid supporting device and a sewer well. The well lid supporting device is in a frustum shape and comprises an upper supporting face, a lower supporting face and a side wall, wherein the upper supporting face is parallel to the horizontal plane and can abut against the lower surface of a well lid; the lower supporting face is in a drum shape and has two long axis edges and two short axis edges, the long axis edges can be connected with the well wall in a clamped mode, and gaps exist between the short axis edges and the well wall; the side wall is connected between the upper supporting face and the lower supporting face. The well lid supporting device can disperse the load on the well lid, when the well lid is damaged or lost, the well lid supporting device can prevent pedestrians or vehicles from falling into the sewer well, and therefore the potential safety hazards of personal safety are reduced, and the purpose of improving the protection safety of the sewer well is achieved.