In order to meet the M2-level life test target proposed by an UHV miniaturized circuit breaker product

a test system containing buffer pressure testing and displacement testing is set up to test and analyze the super-highpower disc spring hydraulic operating mechanisms used by the circuit breaker.In view of the test results of ’not stop in the end’when circuit breaker is opening

the optimization design method combining with buffer pressure test and simulation is used

on the basis of the buffer pressure test and hydraulic system simulation when opening

taking the maximum buffer pressure of the mechanism as the optimization target

the break buffer parameters are optimized

and the buffer improvement scheme is proposed.After the improvement

the buffer pressure has been greatly improved

solves the problem of "not stop in the end" when opening

let the circuit breaker passes the M2-level life test verification stipulated by GB 1984—2014 successfully

and achieves the product’s design goal.The results of the study verify the validity of the optimization method in this paper and have guiding significance to the buffer optimization design of disc spring hydraulic operating mechanisms.