The invention relates to a power station high-temperature pipe system maintenance method based on the non-probability reliability theory. The power station high-temperature pipe system maintenance method includes the steps of conducting finite element calculation on the strength of a power station high-temperature pipe system, determining key detection parts of the power station high-temperature pipe system, determining creep damage parameters with the non-probability reliability theory, building a creep damage probability model by determining the creep damage parameters, calculating structural failures according to the creep damage probability model, building a maintenance method model based on reliability analysis according to detected data, materials of the power station high-temperature pipe system and structure test results, and determining the optimum maintenance time of the high-temperature pipe system according to the maintenance method model and the actual engineering maintenance cost. The non-probability reliability maintenance method is achieved through the power station high-temperature pipe system, the structural probability reliability is efficiently and accurately determined, maintenance plans can be accurately determined, the maintenance method can solve similar problems of high-temperature pipes in other fields, and therefore the application range is wide.