The electromagnetic losses generated at the armor rod segment of lighting wire are the main heat source for the high temperature of armor rod segment. The local high temperature may cause damage to the lightning wire. Based on the actual distribution characteristics of the contact points between the lightning wire and armor rod, a three-dimensional electromagnetic field simulation model of armor rod segment was established by Comsol. The electromagnetic losses density distribution of armor rod segment obtained by simulation was analyzed and discussed. Subsequently, the steady-state temperature rise experiment and the contact resistance measurement experiment were combined to verify the accuracy of the simulation model. Based on the simulation model, the relationship between the electromagnetic losses of armor rod segment and the relative permeability of steel and twisting parameters of stranded wires was explored. The research results show that the simulation models are accurate enough and the error is less than 6%. The electromagnetic losses of armor rod segment are mainly concentrated on the contact points between lightning wire and armor rod. The electromagnetic losses of each row of contact points gradually decrease with the increase of the axial distance. In addition, the electromagnetic losses of the armor rod segment are positively related to the relative permeability of steel and the axial distance of adjacent contact points.