A method for determining the service life of high-voltage circuit breakers based on an object model under conditions of information uncertainty includes decomposing the object into separate functional units, determining their TS and probability of failure using linguistic models, combining partial conclusions about the TS of individual elements based on information obtained on a circuit breaker taken out of service for repair maintenance with the results of monitoring the parameters of the TS in operating modes, which provides an aggregate assessment of the TS, determining the service life and probability of failure.