The utility model discloses a cover assembly device of a diaphragm spring clutch. The clutch cover comprises an inner ear pressing disc, a double-end forming supporting rivet, a transmission belt, a supporting ring, a diaphragm spring and a pressing disc rivet, a pressing disc riveting hole fixed to one end of the transmission belt is formed in the inner ring of the inner ear pressing disc, and the double-end forming supporting rivet penetrates through the riveting hole of the clutch cover and the riveting hole of the diaphragm spring to be riveted and fixed to the other end of the transmission belt. The clutch cover has the advantages that the radial size of the whole clutch is reduced, the arrangement space required by the clutch is greatly reduced, the structure of the cover is simplified, and the cost is reduced.