Clamping and fixing device

The invention discloses a clamping and fixing device which comprises a rack, a driving device and at least two clamping blocks, wherein the at least two clamping blocks are arranged on the rack and can relatively slide under the driving of the driving device, and finally the at least two clamping blocks enclose a clamping groove for clamping a workpiece; and during use, the workpiece needed to be clamped, such as a hydraulic cylinder body, is placed among the at least two clamping blocks, the at least two clamping blocks are driven to be folded by the driving device to form the clamping groove for clamping the workpiece. The clamping and fixing device is simple in structure and easy to operate; compared with a fastening manner by bolts in the prior art, the clamping and fixing device is short in time consumption; and during manufacture, by adjusting the arranging direction of the clamping groove, the clamped workpiece can be in a vertical or inclined state according to needs, so that the repair work of a hydraulic cylinder can be facilitated, and the repair work efficiency is improved.