A new method for measuring the contact angle is proposed for a specific “conduc t ive substrate/insulating film” model about electrowetting effect.The experiment al device based on the new method is built by using the flat electrode instead of the traditional needle electrode and using v erticalphotograph instead of the traditional profilephotograph,which consists of a micro-photographic system,a micro-droplet test box,a reflection light source and a transmission light source.A series of ring contour maps are extracted under different voltages,and the inner and outer diameters of the rings are measured.combined with the relat ionship between disparity of inner and outer diameters and contact angle,the curve of contact angle can be obtained with the change of voltage.The experimental results show that the electrowetting effect of conductive droplets is consistent with the theoretical value.Compared with the traditional method,this new method has the advantages of simpler operation and higher precision.