A bending test device and system for a flexible display device is provided. The bending test device has a bending device. The bending device has a bending shaft, an upper bending plate, and a lower fixing plate. An upper clamping plate is disposed on a surface of the upper bending plate. The upper clamping plate is configured to slide along the surface of the upper bending plate. A lower clamping plate is disposed on a surface of the lower fixing plate. The lower clamping plate is configured to slide along the surface of the lower fixing plate. A first tension measuring element connects to an end of the upper clamping plate. A second tension measuring element connects to an end of the lower clamping plate.