This paper proposes a closed-loop homing guidance law with the constraints of the impact time and angle for the intercepting a constant-velocity target. In order to achieve the required terminal constraints， the line-of-sight （LOS） profile of the missile is modeled as a polynomial with one tuning parameter that is selected via an online optimization routine. Then， a terminal sliding mode guidance law is developed to nullify the tracking error within a fixed time. The key feature of the proposed guidance law is that it does not require the information of time-to-go estimation and the predictive intercept point. Numerical simulations are conducted to demonstrate the effectiveness and robustness of the proposed guidance law.