For fixed-trim vehicle against maneuvering targets,a spiral guidance law is presented. Firstly, a mathematical model is established for describing relative motions between vehicles and maneuvering targets with the error angle and the error plane. Influence on the terminal velocity caused by the error angle is discussed. After that, continuous nonlinear error angle command is designed considering the vehicle control ability. Then, acceleration of maneuvering targets on the ground is estimated by the extended state observer, and virtual target motion information is got by the prediction model. Finally, an exponential convergence terminal guidance law is designed with virtual target added in. Numerical simulation results show that the proposed terminal guidance law is effective for fixed-trim vehicles against maneuvering targets on the ground and that it is robust.