To realize the free falling test mass (TM) in gravitational wave detection in space, an alternative current (AC) electrostatic control strategy is proposed and developed. It is significant to test and verify the AC control actuation scheme on the ground. In this paper, a two-stage torsion pendulum is used to test the performance of the AC control actuator of inertial sensor for Tianqin project. First, the pendulum facility combined with a TM, a capacitive position sensor and an AC control actuator is constructed. Experimental results show that the sensitivities of the pendulum achieve 4.2 × 10^−11 N Hz^−1/2 at 6 mHz and 1.6 × 10^−13 Nm Hz^−1/2 at 15 mHz, respectively, and the pendulum provides a chance to realize the performance test of two degree-of-freedom sensitivities of the actuator, experimental verification of AC control strategy and so on, which is first reported to test performance of the AC control actuator of a space inertial sensor on the ground.