Contact tube wear is the bottleneck of industrial application for non-copper-coated solid wire. It is crucial that we understand the wear mechanism of contact tube so that we can decrease contact tube wear. The effects of temperature and heat input on contact tube wear were investigated in this work. The results demonstrated that fatigue peeling was the main wear mechanism of the contact tube at room temperature without supplying a welding current. Adhesive wear, oxidative wear and abrasive wear were the primary wear mechanisms of the contact tube at 450 °C without supplying a welding current. The wear rate of the contact tube during welding was significantly enhanced in comparison with the wear rate at 20 °C and 450 °C. The effect of contact tube temperature on the wear properties of the contact tube was limited. The wear rate of the contact tube was increased with increasing heat input for non-copper-coated solid wire. The wear mechanism of the contact tube was converted from oxidative wear to arc ablation at the heat input of 9114 J/cm.