Abstract: Segment-moving heat source model of strip-shape is high computational efficiency in the numerical simulation of the welding residual stress and distortion of large welded structures.To improve the computational efficiency,the influence of the different welding speed on the strip characteristics of welding temperature field is analyzed by experiments.And expressions of node heat flow and loading time in the segment-moving heat source model with the strip-shape and combined distribution of heat flux are derived based on the established circular heat source model of the combined distribution of heat flux.The results show that the longer section of the temperature field has already the strip shape as the welding speed is more than 4 mm/s.In addition,comparing with the expressions of node flow and loading time of segment-moving heat source model with the strip-shape and Gaussian distribution of heat flux,the derived expressions relate to not only the heat input sum but also the heat splitting ratio of arc and droplet.