Wire arc additive manufacturing（WAAM） technology is a high-efficiency and low-cost metal manufacturing method.However,the travel speed of the torch cannot keep constant when fabricating complex parts,which is restricted by varied curvature of the path. Therefore,t is difficult to obtain consistent forming appearance. To deal with this problem,a speed planning algorithm under the technology constraint based on NURBS interpolation is proposed,which considers the allowable speed fluctuation of the WAAM technology. It aims at reducing the speed fluctuation during the manufacturing process and improving the consistency of the forming appearance. The maximum relative error does not exceed 5%,meeting the forming control requirements for arc additive manufacturing.