During the manufacturing process of three-dimensional integrated circuits (3-D ICs), many defects may occur in through-silicon vias (TSVs). These defects affect the integrity of the signal passing through TSVs, therefore detecting these defects in the early production stage is crucial. This article proposed a built-in-self-test (BIST) method with a simple test structure and easily implemented fault detection process. Due to the fact that the defects in TSVs influence the charge/discharge speed of TSVs’ equivalent capacitance, a weak current source is designed as the central part of the proposed test structure, which can measure the TSVs’ charge/discharge speed and quantify it using digital values. The effectiveness and robustness of the proposed method is validated by HSPICE simulation. The minimum measurable fault, test time, and test circuit area are also assessed in this article. The simulation results show that the method this article proposed can detect weaker faults, compared with the traditional test methods.