The invention discloses a bridge pier deformation testing device based on the image-digital interaction technology. The device comprises a plurality of observation points arranged on the surface of ato-be-tested pier, and a plurality of industrial cameras arranged at different directions of the to-be-tested pier. All the industrial cameras are connected with an image-digital interaction analysisdevice. The invention further discloses a bridge pier deformation testing method based on the image-digital interaction technology. The method comprises the steps of spraying the plurality of observation points on the surface of the to-be-tested pier; arranging the plurality of industrial cameras at different directions of the to-be-tested pier; loading the to-be-tested pier according to the testworking condition; continuously recording the loading process of the to-be-tested pier through the industrial cameras and sending the recorded information to the image-digital interaction analysis device in real time; analyzing the movement tracks of the observation points by the image-digital interaction analysis device to obtain the dynamic process of the three-dimensional deformation of the to-be-tested pier. According to the invention, by means of the testing device and the testing method, the deformation of the pier can be comprehensively, three-dimensionally, accurately, reliably, continuously and visually reappeared in the non-contact manner.