A cable structure health monitoring method based on strain monitoring is characterized by establishing a mechanical calculation basis model of the cable structure according to the design drawing, completion drawing, measured data and the like of the cable structure based on strain monitoring, carrying out a plurality of times of mechanical calculation on the basis of the mechanical calculation basis model and obtaining the unit transformation matrix of the monitored quantity of the cable structure through calculation. The variation of the health state of the cable structure can be identified,namely identifying support displacement, damaged cables and slack cables on the basis of the approximately linear relationship among the current numerical value vector of the measured quantity, the initial vector of the measured quantity, the unit transformation matrix of the monitored quantity of the cable structure and the current health state vector of the evaluated object to be obtained.