The invention discloses a circuit breaker failure protection apparatus and method under a 3/2 wiring way. The apparatus comprises a circuit breaker state acquisition module, a circuit breaker tripping instruction acquisition module, a current signal acquisition module, a voltage signal acquisition module and a circuit breaker failure discriminating module, wherein the circuit breaker failure discriminating module is used for performing failure discriminating on each circuit breaker in a string according to signals collected by each acquisition module. The circuit breaker failure protection apparatus, by monitoring related tripping instruction and switch-on and switch-off state information as well as electrical quantity information of each circuit breaker in a string at the same time, completes the failure protection function on each circuit breaker in the string; and a state criterion of an adjacent circuit breaker is used as a criterion for judging whether a certain circuit breaker in the string is in failure or not when judging whether the certain circuit breaker in the string fails or not. By adoption of the circuit breaker failure protection apparatus and method, the failure protection criteria can be perfected, and adaptivity of the failure protection can be improved; and in addition, the external loop wiring can be simplified, the quantity of apparatuses can be reduced, and the cost can be lowered.