The design of a series of microwave dielectric resonator with different ratio of diameter to length is proposed in this paper. Based on the principle of short-parallel plates method, an automatic test system with the vector network analyzer and short-parallel plate test fixture for dielectric ceramics resonator is developed. The relationship between the single or multiple work mode of ceramics resonator with different ratio of diameter to length is clarified, and the impact of multimode on the measurement parameters is analyzed. Furthermore, a set of software for the design of ceramic dielectric resonator with different size is developed, which eliminates the influence of multi-mode phenomenon introduced by the unreasonable size of the sample.