Side window detection is usually used in near space kinetic interceptors, which is needed to make the attitude orientation and the line of sight angle stable to ensure the stability of the view. However, the orbit control thruster straps down in the missile body, and the output size and direction are constant, which makes the control of longitudinal and lateral planes interact with each other. In this paper, a finite time convergence guidance law and a pseudo-rate pulse modulator are designed to solve the problem. Firstly, three-dimensional movement relationship between missile and target is established, which includes orbit control thruster. Secondly, the finite time convergence guidance law is designed and its finite time convergence characteristic is proved. What’s more, pseudo-rate pulse modulation is introduced to solve the problem of continuous input digitalization and phase lag by pulse width pulse fregucncy(PWPF). Finally, the influence of different guidance law, target maneuvering characteristics and switching machine threshold is analyzed. The simulation results show that the LOS angular rate converges to zero in finite time before the end of terminal guidance. The guidance law is robust to maneuver target, has higher guidance precision and can ensure the stability of the detection field of view.