The invention provides a method for detecting the total alkaloid content of dendrobium candidum. Compared with the existing dendrobium candidum acid dye colorimetric method, the method first uses sanguinarine as a standard product to replace dendrobine so that a sample to be tested has the maximum absorption wavelength (410nm) the same to that of a complex produced by the reaction of the standardproduct and an acid dye. Preferably, bromophenol blue is used as the acid dye so that the background absorption value is reduced. The novel method has the advantages of high accuracy, good stability and easy reproduction. The method provides the accurate and effective detection method for studying the accumulation rule of total alkaloids of dendrobium candidum and the quality control of the dendrobium candidum total alkaloid preparation process.