Lightweight tool for testing bending fatigue performance of composite material

The invention relates to the technical field of composite material performance testing, in particular to a lightweight tool for testing the bending fatigue performance of a composite material, which comprises an upper slide rail, a lower slide rail and four clamps for clamping a test piece, the clamp comprises a plate body, an upper groove is formed in the top of the plate body, a convex groove is formed in the bottom of the plate body, a fixing frame is installed in the upper groove and hinged to the plate body, a loading block is arranged at the bottom in the fixing frame, an adjusting sliding block is arranged above the loading block, and an adjusting screw rod is arranged at the top of the adjusting sliding block. The top of the adjusting screw rod upwards penetrates out of the fixed frame and is connected with an adjusting nut; two clamps are correspondingly inserted into the two ends of the lower sliding rail through the convex grooves, and the other two clamps are inverted and correspondingly inserted