With the rapid development of aerospace and weaponry, high efficiency and low cost manufacturing for large, integrated and high–performance metal component is in imperious demand. Wire and arc additive manufacturing (WAAM) is a kind of digital manufacturing technology with great potential to the industry. Compared to laser and electron beam additive manufacture, WAAM has many advantages, such as high material utilization, high deposition efficiency and low equipment cost. This paper provides an overview of researches of WAAM on macro forming accuracy, microstructure and mechanical properties of metal components, meanwhile, the main encounting problems of WAAM are also put forward. In order to solve these problems, the WAAM and its hybrid manufacturing technologies are reviewed, including ultrasonic peening or laser peening, cold rolling and hot rolling process, high–frequency micro–forging and post–treatment process. Finally, the key technologies to be solved of WAAM and its hybrid manufacturing are summarized.