Abstract: In order to observe the microscopic structure of Dendrobium officinale quickly and efficiently. This study used the light microscope and the improved sucrose protection-liquid nitrogen quick-freezing freezing section method for orchid tissues and organs, Which improved sucrose protection-liquid nitrogen frozen method, observed root, stem and leaf of microscopic structure on D. officinale. The technology and methods treated D. officinale with sucrose phosphate buffer protection fluid,and then Vacuum processing. By liquid nitrogen frozen, embedding, sectioning, exhibition slice observation, staining and photo produced D. officinale roots, stems and leaves a complete microscopic section. The results show that the optimal condition for root was 8% sucrose mass volume fraction, condensation temperature -25℃, slice thickness 20 μm; the optimal condition for stem was 16% sucrose mass volume fraction, frozen temperature -20℃ and slice thickness 15 μm; the optimal condition for leaf was 4% sucrose mass volume fraction, frozen temperature -20℃ and slice thickness 10 μm. The study on the Orchidaceae microstructure observation and histochemical study will have broad prospect of application.