The invention discloses a spring operating mechanism for a circuit breaker, relates to the field of high-voltage switches, and aims to provide a spring operating mechanism for the circuit breaker, which is short in brake separating and closing time, stable and reliable in mechanical property, low in energy loss and small in size. The spring operating mechanism for the circuit breaker provided by the invention comprises a first side plate and a second side plate; an energy storage system, a brake closing and brake closing control system and a brake separating and brake separating control system are integrated on the first side plate and the second side plate. The energy storage system comprises an energy storage shaft, an energy storage gear, an auxiliary cam, a first energy storage crank arm, a second energy storage crank arm, a motor, a chain and an energy storage spring component; the brake separating and brake separating control system comprises an output shaft; an output crank shaft, a special-shaped crank arm, a buffer arm and a central crank shaft are arranged on the output shaft in a penetrating manner in sequence; two brake separating springs are mounted on the central crank shaft; the brake closing and brake closing control system comprises an energy storage latch; the upper end of the energy storage latch and a brake closing limiting bearing are mounted in a matched manner; a brake closing limiting latch is in contact with the energy storage latch.