The invention provides a stirling engine. The stirling engine comprises a first cylinder, a second cylinder, an air moving piston and a power piston. The stirling engine is characterized in that the bottom end of the power piston is arranged to a magnet, and a guide groove is obliquely formed in the periphery or the inner wall of the power piston; a driving block which is in match with the magnet by magnetic attracting through a clearance manner is arranged on the air moving piston; a flywheel is arranged on the top end of the second cylinder through a rotating shaft; the rotating direction of the flywheel is perpendicular to the moving direction of the power piston; the rotating shaft is downwards connected with a driving rod; the end part of the driving rod is arranged in the guide groove and can move along the guide groove. The invention further discloses a cup cover and a cup which are both provided with the engine. Compared with the prior art, the stirling engine has the advantages that the power piston drives the flywheel through the driving rod to rotate in the horizontal direction, so that the structure and type of the existing stirling engine model is enriched; the whole structure is compact, and the design is nice.