Aiming to solve the problems of lack of detection and sorting equipment for component-type germplasm and low detection efficiency, a seed detection and sorting device with double composite vibration seed metering was designed. The seeds were flattened through double composite vibration, and the sorting component selected high-quality seeds according to the detection results. The device consisted of key components such as the seed metering component, detection component, and sorting component. Structural design and theoretical analysis were carried out on the key components to design better components. Taking corn seeds as the test object, the voltage and vibration frequency ranges of the feeding tray and the leveling tray were determined through single-factor tests. With the qualified rate of seed spacing, seed fitting rate, and seed residual rate as the test indicators, a four-factor and three-level test was carried out, and a response surface mathematical regression model was established to analyze the influence of each factor and their interactions on the operation of the device. The results showed that when the voltage of the feeding tray was 60 V and the vibration frequency was 46. 0 Hz, the voltage of the leveling tray was 55 V and the vibration frequency was 51. 6 Hz, the seed metering effect of the device was optimal. The test verification with the optimal parameters showed that the qualified rate of seed spacing was 90. 5%, the seed fitting rate was 2. 9%, and the seed residual rate was 2. 3%. The sorting speed of the device can reach 1 000 seeds/min, which met the requirements for the selection and storage of germplasm resources.