The invention provides a buckling strength testing device for stirrups. The testing device comprises an upper bracket, an upper bracket supporting device, two buckling devices, at least two buckling adjusting parts, a lower bracket, a lower bracket supporting device and two clamping devices. The upper bracket supporting device is disposed at the middle part of the upper bracket. The top of the upper bracket supporting device is fixedly connected to an upper connector or an upper connecting port of a micro-electronic universal tester. One side of the upper bracket supporting device is provided with a gap. The buckling devices are disposed at the top of the upper bracket and can move along the extending direction of the upper bracket. The buckling adjusting parts are stuck on projected parts of the buckling devices. The lower bracket supporting device is disposed at the middle part of the lower bracket. The bottom of the lower bracket supporting device is fixedly connected to a lower connector or a lower connecting port of the micro-electronic universal tester. The clamping devices are disposed at the top of the lower bracket, can move along the extending direction of the lower bracket, and are used for clamping free ends of a stirrup to be tested. Through the testing device, properties of stirrups with different widths, different buckling angles and different radiuses of curvature can be tested, and influencing rules for the buckling strength of the stirrups can be analyzed.