The invention relates to a method for identifying loose supporting ropes based on space coordinate monitoring during support settlement, which is based on the space coordinate monitoring and determines whether a mechanical calculation reference model of a structure needs to be updated or not by monitoring the coordinates of a support of the structure. Only when the coordinates of the support of the structure are changed, the mechanical calculation reference model of the structure is updated, thereby obtaining a novel mechanical calculation reference model of the structure, which is reckoned in the support settlement of the structure. On the basis of the model, a change matrix of the unit damage quantity to be monitored is obtained by calculation. According to an approximately linear relationship among the current vector of the strain, the initial vector of the strain, a change matrix of the virtual unit damage strain and the current virtual damage vector, virtual damaged ropes can be calculated and identified, and the residual virtual damaged ropes are just loose ropes, i.e. ropes the rope force of which needs to be regulated after a true damaged rope is distinguished by using a nondestructive examination method, so that the rope length which needs to be regulated can be determined according to a relationship between the looseness degree and the virtual damage degree.