The invention relates to a transmission system and a design method for a circulation type stereo garage with the variable chain plate length. Chain plates which are each composed of a chain plate fixed arm and a chain plate movable arm are adopted, the chain plate movable arms are stretched out in rotation areas through telescopic connection of the chain plate fixed arms and the chain plate movable arms and the appearance arrangement of a hanging beam shaft guide rail, and therefore under the same vehicle carrying frame transverse clearance, the vehicle carrying frame longitudinal clearance smaller than that in the prior art is achieved, the size of the circulation type stereo garage is reduced, and the space utilization rate of the circulation type stereo garage is increased. Optimal parameters for reducing the size of the stereo garage are provided for design of the stereo garage. By means of the arrangement of the hanging beam shaft guide rail appearance of the rotation areas belowthe stereo garage and the radius of transmission wheels, there can be two vehicle carrying frames parked and stopped at the positions, close the ground, under the vertical circulation type stereo garage at the same time, the number of vehicles which are stored and taken at the same time is increased to two, and the user wait time is shortened.