An auto test system is designed in this paper

which can test all the specifications of the MEMS-based Variable Optical Attenuators（VOA）expediently and enable the optical spectrum analyzer to share the test results with the polarization controller.By programming

data are displayed and curves are plotted in real-time

and data can be stored in the database automatically.Compared with the normal test instruments

this system is low in manufacturing cost

high in measuring accuracy and has high application values.