The invention relates to a clamping device. The clamping device comprises clamps, a locking pin, a tightening pipe and a core shaft, wherein a connecting hole is formed in the clamps; the locking pinpenetrates through the connecting hole, and comprises an elastic part and a locking part connected with the elastic part; the core shaft penetrates through the tightening pipe to be connected with theclamps; a releasing part is arranged at the far end of the core shaft, and is connected with the locking pin; the tightening pipe is provided with a locking position; when the clamps are located at the first position, the releasing part is used for restricting the locking pin and compressing the elastic part to enable the locking part to be separated from the locking position; and when the clampsare located at the second position, the releasing part releases restriction to the locking pin, the elastic part is sprung back, and the locking part extends into the locking position for locking. After being closed, the clamps are locked, firm locking is realized, and the situation that the clamps are opened once again can be avoided.