The invention provides a dismounting method of an energy storage spring for a 10 kV metalclad withdraw switchgear circuit breaker. The method is implemented with a special tool. The special tool includes a body, a driving assembly mounted on the body, two sets of clamping stretching-contracting assemblies drivingly connected to the driving assembly and an auxiliary stretching-contracting assemblywhich is drivingly connected to the driving assembly and pinned to the two sets of the clamping stretching -contracting assemblies. The dismounting method includes cutting off a power supply of the circuit breaker, removing a handcart air plug of the circuit breaker, manually opening and closing a switch to release energy of the circuit breaker mechanism, adjusting the special tool to a ready state, holding and stretching the energy storage spring by using the special tool, dismounting a connecting lever fixing nut and removing a rotating connecting lever when the stretching length of the energy storage spring facilitates the removal of the rotating connecting lever arranged on the lower end of the energy storage spring, removing the energy storage spring for maintenance and the like. Thedismounting method of the energy storage spring for the 10 kV metalclad withdraw switchgear circuit breaker can be suitable for the dismounting of conventional various types of energy storage springs,is strong in applicability and convenient in operation, and improves the work efficiency.