The invention relates to a progressive health monitoring method for a cable system in a cable structure on the basis of cable tension monitoring. On the premise of taking cable tension as the monitored value, the progressive health monitoring method considers that linear relations among a current value vector of a monitored value, an initial value vector of the monitored value, a value change matrix of the unit damage monitored value and a current nominal damage vector are approximate, and particularly nonlinear relation characteristics between the vectors are more obvious when the number of damaged cables is numerous or the damage degree is larger. The invention provides the method for piecewise approximation of nonlinear relations by the linear relations on the basis of cable tension monitoring in order to overcome the defects. The method splits a large section into a plurality of continuous subsections; the linear relations in each subsection is accurate enough; and a non-inferior solution of a current cable damage vector can be calculated in each subsection by a proper algorithm such as a multiobjective optimization algorithm, so that the position and the damage degree of a damaged cable can be accurately determined.