A cylinder cover standard sample piece of an engine valve clearance control system belongs to the detection technical field. The middle part of the upper end surface of a main matrix is successively provided with a left location pinhole matrix, a right location pinhole matrix and a keel, wherein an exhaust side belt pulley shaft neck hole matrix and an exhaust side locating plate, and an air inlet side belt pulley shaft neck hole matrix and an air inlet side locating block are separately arranged on the two sides of the left location pinhole matrix, the periphery of the upper end surface of the main matrix are provided with an exhaust side positioning table No. 1, an exhaust side positioning table No. 2, an air inlet side positioning table No. 1, and air inlet side positioning table No. 2 in turn, all air inlet side components and exhaust side components are successively arranged on the two sides of the keel and fixedly arranged on the plane of the main matrix, and the lower end surface of the main matrix is provided with a bottom surface positioning body No. 1, a bottom surface positioning body No. 2, a bottom surface positioning body No. 3 and a bottom surface positioning body No. 4. The invention has the advantages that the prepared cylinder cover standard sample has high precision, light weight, wear resistance and long-term stable sample piece critical dimension, and is convenient to fetch.