The invention provides a fully-enclosed spring operating mechanism for a ring main unit. The fully-enclosed spring operating mechanism comprises an energy storage member, a switch-on holding and switch-off member, a transmission mechanism member and a state display member which are disposed on a support sheet metal member. The energy storage member provides kinetic energy for the transmission mechanism member by means of manpower or a motor in order to achieve switch-off. The switch-on holding and switch-off member holes a switch-on state and achieves a switch-off operation. The state display member displays switch-on and switch-off states. Respective components are integrally enclosed. The mechanical strength requirement and the cost of the fully-enclosed spring operating mechanism for a ring main unit are reduced, and the operating mechanism is fully enclosed.