Parachute system is a significant composing part of aircraft, and the swing angle is one of system security targets. To the complicated measurement problem of parachute angle in wind tunnel test, this paper describes a test method based on stereo vision system, the system is mainly composed of two CCD cameras, image acquisition card and computer. It can get 3D coordinates by stereo vision calibration and digital image processing technology, and calculate the parachute swing angle by geometry relationship. The result shows that the method succeeds, and gets the vertical and horizontal angles which are projected onto two orthogonal planes. The method has the advantage of simple system composing and good compatibility, displays much better application value.