Introduction: Elasticity refers to the recovery state under stress and deformation, which is particularly important for the elastic performance of the star elastic coupling. Star elastic coupling has the excellent performance of shock absorption buffer, elastic coupling many kinds, roughly divided into metal and non-metal elastic coupling, their common place is the two half coupling and elastic components to achieve torque transmission, the elastic component _ is the coupling accessories of the elastic coupling. For example, the coupling accessory of HL elastic pin coupling should be nylon pin, and the elastic component of metal elastic element diaphragm coupling is diaphragm, which should be its coupling accessory. Choice of star elastic coupling: There are many manufacturers of star-shape elastic coupling. The price competition node of coupling cost performance should be the price comparison of the durability of coupling accessories and the matching state of the overall service life of the two-half coupling and the specific transmission equipment. While the simple low price leads to the coupling accessories are vulnerable, the two-half coupling is scrapped prematurely and fails, and the simple excellent coupling also increases the purchase cost of the coupling user. This should be the joint concern of coupling users and coupling manufacturers. To sum up: Although the strength and fatigue strength of the star-shaped elastic coupling accessories are important, the strength and fatigue strength of the two-half coupling are related to the durability of the coupling accessories, but also affect the user cost of the coupling (the premature deformation and scrap of the two-half coupling, the need to buy the coupling again at the same time, it is also a bad influence on the overall strength performance of the transmission equipment). This is the need for coupling manufacturers and coupling users common concern.