Four-point bending fixture of thin plate for high stress loading and loading method thereof

The invention discloses a four-point bending fixture of a thin plate for high stress loading and a loading method thereof. The fixture comprises a fixture body. The fixture body comprises a horizontalbottom plate, vertical side plates arranged on the two sides of the horizontal bottom plate and fixedly connected with the two sides of the horizontal bottom plate, and two top plates arranged at thetops of the vertical side plates on both sides and arranged to face each other; a horizontal bottom plate, two side vertical side plates and two top plates encloses a top-opened accommodating cavity,and the cross section of the accommodating cavity is in a rectangle shape; a loading block is arranged in the accommodating cavity and arranged in parallel with the horizontal bottom plate for carrying a thin plate sample, a loading force hole is arranged at the center of the bottom of the loading block, a loading screw is arranged at the center of the horizontal bottom plate, the top end of loading screw vertically penetrating through the horizontal bottom plate can be embedded in the loading force hole of the loading block to butt. The fixture of the invention can place the thin plate sample between the loading block and the two top plates, can effectively avoid problems of unstable loading of the thin plate sample or ejection of the sample and the like.