A new voice coil actuator is developed for suiting to the application of active vibration isolation system (AVI), and a series of experiment are made to get its dynamic performance. Firstly, a mathematical model of voice coil actuator is proposed in order to design it by length of coil, magnetic flux density, and input current signal. A mechanical design using the ball caster is adopted to avoid in touch between the voice coil and iron yoke. The performances of the voice coil actuator are investigated in the frequency domain and finally validated by the test of active vibration isolation. The experimental results show that the rated output force can reach 3N suited to application in AVI.