A binding force testing device for testing the binding force of a hinge, includes a control chassis for controlling the binding force testing device; a platform mounted on the control chassis; a support mounted on the control chassis above the platform; a first driving device mounted on the support; a main holder mounted on the first driving device facing the platform; and a second driving device mounted on the support and connected to the first driving device. The first driving device drives the main holder to move relative to the platform in a first direction; the second driving device drives the first driving device to move relative to the platform in a second direction perpendicular to the first direction.