Dendrobium officinale Kimura et Migo homologous tetraploid was identified by means of stomata chloroplast chromosome counting and flow cytometry. On the basis of this, the multiplication efficiency was compared between the two schemes of stem segment propagation and protocorm induction, multiplication and differentiation, and the ploidy stability of protocorm was reidentified. The results showed that：（1） the strain ‘Huazi2’ in the laboratory was a pure contract tetraploid. （2）The best medium for propagation of stem segments was MS+2.0 mg/L 6BA+0.5 mg/L NAA+15% banana juice. For stem segment protocorm induction, the best culture medium for corm is MS+1.0 mg/L 6BA+0.5 mg/L NAA+0.2 mg/L KT, the inducing rate is 76.66%; The best medium for protocorm multiplication is MS+1.0 mg/L 6BA +0.5 mg/L NAA+15% potato extract. The best medium for protocorm differentiation is 1/2 MS+ 0.5 mg/L 6BA+20% potato extract， the protocorm differentiation rate was 85.70%; The best medium for rooting is 1/2 MS + 0.5 mg/L NAA+15% banana juice, the rooting rate was 92.77%.（3）The result of root tip identification of protocorm showed that the ploidy induced could be inherited stably.（4）The best time of transplanting was 5 days, and the survival rate of transplanting was 92.30%. A new rapid propagation technique system of autotetraploid lines of Dendrobium officinale Kimura et Migo was established in this experiment, which established the foundation for the industrial production and popularization of tetraploid plantlets.