The invention relates to an establishing and determining standard of a method for determining
dendrobium fimbriatum
purebred similarity, and a determining method. The determining method comprises thesteps of S1, acquiring a
dendrobium fimbriatum sample which is same with a
gene sequencing conclusion, and measuring the total length of each sample; S2, performing normality testing on a sample totallength variable; and S3, a
standard interval: if a result obtained in the step S2 satisfies normal distribution, obtaining a 95%
confidence interval of a mean value and a 95%
confidence interval of astandard difference according to a normal distribution total calculating formula; wherein the
confidence interval can be used as a standard range for discriminating purity of an unknown sample. The establishing determining standard according to the actual acquired data is characterized in that the 95% confidence interval of the mean value and 95% confidence interval of the standard difference arerespectively (50.0149,66.6251) and (15.7102,27.9898); and the tested
dendrobium fimbriatum sample is compared with the intervals. According to the method of the invention, the
breed purity is determined through a characteristic related with
dendrobium fimbriatum morphology, thereby simply determining the value of the artificially planted
dendrobium fimbriatum or whether the artificially planted
dendrobium fimbriatum has a value; high identification accuracy is realized; and an important reality meaning is obtained.