The invention provides a well lid. The well lid comprises a lid body, a heating element and a power supply. The heating element is arranged on the lid body. The power supply is connected with the heating element and used for supplying power to the heating element to enable the heating element to generate heat energy. At low temperature of cold winter, the well lid is mounted on a fire hydrant well and can keep dissipating heat into the fire hydrant well to increase the temperature in the fire hydrant well. The problem that a water pipe in a fire hydrant well is prone to frost cracking or frozen burst in the prior art is solved.