The invention discloses a method for simultaneously detecting the content of multiple components in creatine powder, comprising: accurately weighing a sample, adding purified water, ultrasonically extracting, constant volume of purified water, shaking evenly, and passing through a water-phase filter membrane to obtain Creatine powder test sample; get creatine powder test sample, adopt HPLC to detect, the condition that described HPLC detects is: adopt C18 chromatographic column, with sodium dihydrogen phosphate solution, and adjust pH value to 8-11.5 with ammonia water The mobile phase is used for isocratic elution, and the contents of creatine monohydrate, creatinine, and dicyandiamide are obtained according to the HPLC detection results. The method of the invention can realize rapid separation of the three components of creatine monohydrate, creatinine and dicyandiamide by optimizing the chromatographic conditions, and has good reproducibility. The method of the present invention can eliminate the interference of the by-products dicyandiamide and creatinine in the creatine powder to creatine monohydrate, and can accurately detect the contents of creatine monohydrate, creatinine and dicyandiamide in the creatine powder at the same time, It is beneficial to realize the effective control of the quality of creatine powder.