The invention discloses a clamping structure of a circuit board, which comprises a base, wherein the top of the base is fixedly connected with a box body, a bottom plate is slidably connected betweentwo sides of the inner wall of the box body, fixed blocks are fixedly connected at two sides of the bottom of the inner wall of the box body respectively, one side of the inner wall of each fixed block is fixedly connected with a first sliding block, the other side of the inner wall of each fixed block is fixedly connected with a second sliding block, an upper check block, which is located betweenthe first sliding block and the second sliding block, is fixedly connected between the front and back sides of the inner wall of each fixed block, the bottom end of each rotating rod runs through thecorresponding fixed block and extends to the internal part of the fixed block, and the end, which extends to the internal part of the corresponding fixed block, of each rotating rod is fixedly connected with a fixed rod. The invention relates to the technical field of a circuit board clamping structure. The clamping structure of the circuit board can clamp effectively and can perform adjustment according to different circuit boards, thereby being convenient for fixing and clamping different circuit boards, reducing unnecessary waste, greatly improving the clamping efficiency and being very convenient in use.