Abstract: The optimum extraction condition and measurement method for analysis of folic acid in millet was studied.The red valley millet cultivar from Hebei was used as materials, and a single factor experiment for folic acid extraction and detection was respectively conducted based on the illumination condition, color rendering time, detection ranges, extraction time, usage of absorbent, the consumption amount of elution solution as well as the recovery rate of standard sample.Data showed that 25mL of 0.1mol/L KH2 PO4 was used to obtain the optimum extraction effect by soaking 2.5g millet at 50℃ for 8 hours, and adsorbing for 10 minutes with 0.5g active carbon adsorbent treated by aniline, and continuously eluting five times with 7mL of mixture containing 3% ammonia and 70% ethanol, and then indirect fluorescent method was used to determine the contents of folic acid oxidized by KMnO4, and the satisfactory result was obtained because of higher the recovery rate of 96.14% with a relative lower deviation of 1.68%.