The invention discloses a transparency detection method, system and network. The method comprises the steps of establishing a judgment basis of a critical image when transparency equipment detects transparency, wherein the transparency detection method comprises the steps of using a light source (5) to emit light, observing an image of a marker piece (2) in liquid to be detected by a camera device (3), transmitting an image signal back to a control system (4), and judging the critical image of transparency recognition through the image signal by the control system (4); achieving relative motion between the marker piece (2) and a detection interface of the liquid to be detected until catching the critical image; measuring the distance between the marker piece (2) and the detection interface of the liquid to be detected, wherein the distance value is the numeric value of transparency. The transparency detection method is used for solving the problems that the measurement result is influenced because of vision differences among measurement personnel, the measurement accuracy is influenced by outside light brightness differences, the transparency measurement value cannot be precisely shown, the manual detection efficiency is low, all-whether continuous measurement cannot be carried out.