In order to advance the application of rotating angle in the field of bridge inspection and evaluation， high-precision dynamic testing method was put forward in view of the beam end rotating angle， and corresponding rotating angle testing system was designed and manufactured. Such system connects bridge floor and pier， converts the unknown rotating angle information to the displacement and strain information in turn. With the measured dynamic strain data at high precision， the rotating angle of the beam end measurement point section relative to the pier was inversely calculated. According to specific parameters of the rotating angle testing system， the range， sensitivity， working load and theoretical resolution was analyzed， proveing its obvious advantages in small rotating angle test of beam end. Based on indoor experimental research using the rotating angle testing system， the analysis of multiple test data showed that there is an obvious and stable linear relationship between the strain value and the actual rotating angle. In addition， the testing system has a higher sensitivity which is close to theoretical value. The experimental study further verifies the feasibility of high-precision dynamic measurement of beam end rotating angle based on strain measurement.