In order to make constant displacement pump output of multi flows, and make constant displacement motor output of multi speeds and multi torques, the proportional type and parallel type of gear multi-pump (multi-motor) consisted of several single pumps and motors were designed, a theory of gear multi-pump and multi-motor driving system was presented based on the proportional type and parallel type of gear multi-pump (multi-motor). The principle of two multi-pump (multi-motor) was introduced, two gear multi-pump and multi-motor driving systems were designed based on 1-1 proportional type and 3 parallel type gear multi-pump (multi-motor), and the principle and characteristics of them were introduced, the output characteristics of the two gear multi-pump and multi-motor driving systems in different working ways were analyzed, and the output characteristics of two gear multi-pump and multimotor driving systems consisted of X-Y proportional and Z parallel gear multi-pump (multi-motor) were expanded, the experimental platform of gear multi-pump and multi-motor driving system was built. The result showed that the driving system can output multi speeds and multi torques, and there was a certain ratio between the speed and torque levels. The experimental result was consistent with the theoretical analysis, which showed the correctness of theoretical analysis. The research provided a basis for design and research on multi-pump and multi-motor driving system.