In this paper, a mechanical model of armor wire winding process is established to quantify the relationship between the tension force and the internal force of armor wire cross section in winding process. Then based on this model, a method for predicting the residual stress of armor wire cross section after winding is presented. The reasonable winding tension force and the minimum residual stress are discussed. In addition, the reasonable design of the processing equipment is further discussed. This paper provides a useful reference for the evaluation of key parameters and the prediction of residual stress in the processing of tensile armor layer of offshore flexible pipes and cables.