To provide a cylinder cover for protecting depredation of an impactor and a cylinder, when the impactor dashed down to an auto-body rebounds to encounter the cylinder of a catapult during the period of testing runtime.

In the present cylinder cover which is equipped with a cylindrical adherend section 10 and both an occluded section 20 and a corded extension member 30 formed at one with the adherend section so as to wrap an aperture 10A on one end side of the adherend section 10, the occluded section 20 includes a concave portion or a hole portion into which an impactor mounting section prepared at an apex plane of the cylinder is inserted and a plurality of first lobations 22 formed in a radial pattern from the concave portion or the hole portion, whereas the adherend section 10 includes a groove section formed along a periphery near to the aperture 10A and a second lobation 11 formed along a length direction of the adherend section up to an intermediate portioning in the length direction in succession to the first lobation 22 to fit an extension member 30 in the groove section.