Wire and arc additive manufacturing employs an electric arc as energy beam to melt metal wire layer by layer to fabricate full weld metal components. It is highly praised for its advantages of low manufacturing cost,high deposition rate,and high material utilization. The automatic detection and control of forming dimensions is a key scientific and technical challenge that must be solved to promote the engineering application and rapid industrialization of wire and arc additive manufacturing. This study mainly discusses current research status of the forming control technology in wire and arc additive manufacturing from the perspective of forming process regulation and on-line monitoring and control. Starting from the principle of infrared,electrical parameter and visual monitoring,research progress and shortcomings of existing monitoring and forming control in wire and arc additive manufacturing are analyzed. The main future outlook of on-line monitoring and control in wire and arc additive manufacturing in the future is put forward.