An optical structured illumination of 3D object as a light band method for automatic noncontact wear measurement and defects detection of a contact wire network is presented. The experimental device can extract main technological wire parameters like remaining height with RMS value down to 0.15 mm. Also the cross-sectional area of the wire can be measured with RMS area noise value of 1.5 mm 2 , which is sufficient for a confident decision-making related to the automatic wire wears and defects on railways, tram and trolleybus lines, and similar systems of vehicles electro-supply.