Testing platform for stiffness of member

The utility model discloses a testing platform for stiffness of a member. The testing platform is characterized in that: two end points of the member are respectively provided with a total reflection mirror M0 and a total reflection mirror M1; the laser beam emitted by a laser respectively passes through a total reflection mirror M4 and a half-reflecting mirror M3 to be then reflected respectively to the total reflection mirror M0 and the total reflection mirror M1; after reflected by the total reflection mirror M0 and the total reflection mirror M1, the beam is projected to a screen to form light spots A0' and A1'; and the screen reads the coordinate values of the light spots A0' and A1'. After load P is exerted at the free end of the member, the beam is reflected by the total reflection mirror M0 and the total reflection mirror M1 and then projected to the screen to form light spots A0'' and A1'', the screen reads the coordinate values of the light spots A0'' and A1'', the coordinate values of the light spo