Abstract: In order to study the rapid prototyping of 4043 aluminum alloy using cold metal transfer, arc rapid prototyping systems were built,and 4043 aluminum alloy thin-walled parts were manufactured. The research shows that controlling the current percentage of striking arc and arc extinction may adjust the energy distribution of single arc forming. Meanwhile ,the problem of collapse for striking arc and hump for arc extinction during thin-wall component forming is solved.The effects of welding speed and wire feeding speed on the forming of the parts were summarized. The microstructure of the manufactured part was observed and the mechanical properties were tested according to the appropriate process parameters. The research shows that controlling the current percentage of striking arc and arc extinction may adjust the energy distribution of single arc forming. Meanwhile ,the problem of collapse for striking arc and hump for arc extinction during thin-wall component forming is solved.