A truncation function-based finite-time sliding mode control strategy was presented to address the robust control problem of the second-order nonlinear uncertain system. The advantages of the proposed method are as follows: the system states will converge to zero at the desired finite time; the controlled system is globally robust against external disturbance and parameter variation; the system response can be analytically expressed; the system performance can be tuned by selecting different truncation function. Simulation results validate the effectiveness of the proposed method.