The speed transfer ratio is one of the most important parameters of the double-deck ball bearing. For the calculation of speed ratio, most of the theoretical estimation formulas related to the structure are used, but under some measured working conditions, the speed ratio is not only related to structural parameters. To explore the speed transmission mechanism of double-deck ball bearing, a new method for calculating the speed transmission characteristics of double-deck ball bearing is proposed in this paper. The generalized four-terminal parameter method is applied to the speed analysis of double-deck ball bearing for the first time. The speed transmission analysis model of double-deck ball bearing is established by combining the three theories of quasi statics theory, elastohydrodynamic lubrication theory, and generalized four-terminal parameter theory. A variety of factors are taken into account to solve the research status of rotational speed transfer ratio only considering a single factor. The speed transmission characteristics of the double-deck ball bearing after the system are accelerated to the steady-state are studied, and the correctness of the results is verified by experiments, which provides a new idea for the analysis of the speed transmission characteristics of the double-deck ball bearing, and provides a theoretical basis for the exploration and design of the potential application value of the double-deck ball bearing.