The invention discloses a measurement device for the dynamic stretching crack propagation speed of a fragile material. The measurement device comprises an SHPB (split Hopkinson pressure bar) device, a specimen and a high-speed camera, wherein a round through hole is preformed in the center of the specimen, and the specimen is clamped between an incident rod and a transmission rod of the SHPB device; the high-speed camera is installed on an axis of the round through hole of the specimen. The measurement method comprises the following steps: applying impact load to the specimen by utilizing the SHPB device so as to enable a material to be cracked; meanwhile, shooting an image on the surface of the specimen in real time, confirming the crack starting and stopping time according to the record of the image, measuring the length of the crack actually, and calculating the dynamic stretching crack propagation speed. The measurement device and method provided by the invention can control the dynamic stretching crack propagation direction of the fragile material, and also can precisely confirm the crack propagation starting and stopping time, effectively improve the measurement precision of dynamic stretching crack propagation speed of the fragile material, and provide a novel conveniently operated, rapid, convenient, simple and effective method for confirming the dynamic stretching crack propagation speed of the rock-type fragile material under the impact load effect.