The aim of this research was to develop a high-efficiency and high-material-utilization additive manufacturing technology using the hot-wire laser method. In this study, the optimization of process conditions using a combination of a high-power diode laser with a relatively large laser spot hot-wire system was investigated. The effects of welding parameters such as the laser power, process speed, and wire feeding rate (wire feeding speed/process speed) on the bead appearance evaluation and the cross-sectional characteristics ( e.g. effective width, effective height, maximum height, and near net shape rate) were studied in detail. The process phenomena of the three-layer and multi-layer deposition were investigated by in-situ observation via a high-speed camera. Energy density input and wire feeding rate were found to be dominant parameters influencing both the stability of phenomena and bead appearance. With the increase of process speed, the effective width decreases, the effective height, maximum height, and the near net shape rate increases. Additionally, all measured values of the wire feeding rate of 30 improve compared with the values of the wire feeding rate of 20. The near net shape rate increased and the effective width over 10mm of three-layer deposition for the laser spot width of 11 mm was obtained with suitable process parameters. The defect-free 15-layer wall modeling of more than 50 mm in height, 8 mm in width, and 250 mm in length was obtained with high efficiency using the optimum conditions by the hot-wire laser method.