Abstract:  In wire arc additive manufacturing (WAAM), the inherent layer-by-layer deposition characteristics lead to severe heat accumulation. In the absence of active thermal management or extended interlayer cooling times, this accumulation compromises the geometric consistency of the fabricated components. To address this challenge, this study proposes an iterative compensation method for interlayer heat input based on a thermal resistance model. By deploying multi-channel thermocouples on the substrate, the temperature characteristic curves during the deposition process under various EP currents were captured, enabling a systematic analysis of how heat accumulation affects deposition layer formation. Furthermore, based on the principle of conservation of energy, an iterative compensation model aimed at maintaining consistent accumulated heat within each weld bead was established, thereby achieving effective regulation of the interlayer heat input.