Addressing the relatively slow progress in research on mechanized transplanting technology for Panax notoginseng seedlings in China, as well as the difficulty of traditional automatic transplanting devices in achieving precise posture adjustment and orientation for these seedlings, a Panax notoginseng seedling oriented transplanting device based on the moment imbalance effect is proposed. High speed photography is utilized to analyze the changes in seedling posture under different release attitudes. Experimental results demonstrate that, under the influence of the moment imbalance effect, the cutting edge of the seedlings tends to face downwards. A force analysis of the seedling′s falling process is conducted, revealing the influence pattern of the moment imbalance effect on the seedlings′ posture changes. Through theoretical calculations and simulation analyses, the key components of the orientation device are designed, and a dynamic model of the seedling posture adjustment and orientation process is established, uncovering the mechanism of seedling orientation. To optimize the performance of the orientation device, single factor experiments and Box- Behnken experiments are conducted, with conveying speed, horizontal spacing, and vertical height as the experimental factors, and the orientation qualification index as the experimental indicator. The experimental results indicate that the primary and secondary order of influence on the orientation qualification index is conveying speed, horizontal spacing, and vertical height. When the conveying speed ranges from 90.564 mm/s to 110.468 mm/s, the horizontal spacing was between 24.931 mm and 27.701 mm, and the vertical height was 8.5 mm, the orientation qualification index exceeds 85%. Parameter optimization is then carried out, and the optimized results meet the requirements for Panax notoginseng seedling transplanting.