The invention discloses a bearing capacity matching method and system for a power transmission line system; the bearing capacity matching method comprise the steps of determining the failure sequenceof each component and the safety coefficient of each component in the power transmission line system; calculating the matching adjustment coefficient of each component on the basis of the failure sequence of the transmission line system component and the safety coefficient of each component; and calculating the bearing capacity of each component under different failure sequences on the basis of the matching adjustment coefficients of the components, so that the overall design of the line can be guided, and the reasonability and economy of the design of the power transmission line are improved.