Hydrodynamic drives, hydraulic drives, and friction drives have the common characteristics of continuously variable ratio but lower efficiency in comparison with gear meshing drive. A novel method for the design of power-cycling variable transmission (PCVT) has been proposed, which has the characteristics of continuously variable ratio and high efficiency in the whole working range. First, the power-cycling phenomena of powertrain system have been analyzed, and the basic configuration of PCVT system has been put forward. The feasible judgment criteria and the basic design principle of PCVT system are provided. The calculation formulas of speed ratio characteristic and efficiency characteristic of PCVT system are also derived. At last, the design patterns of PCVT system have been provided for illustrating the unique performance of PCVT system.