Study and establish a method of separation and enrichment of different from the traditional fire assay——small fire assay preconcentration of gold in ores, and the detection method for gold content Flame atomic absorption spectrometer. The optimal small fire assay conditions were determined: flux ratio, borax-soda-yellow lead-starch 5∶5∶10∶1, melting temperature 900 ℃, dosage of protectant 10mg. After the separation and enrichment with best small fire assay condition using 3 g sample, the lead button of the mineral samples got the alloy particle of silver, gold by cupellation. After dissolution in dilute nitric acid, gold was separated from silver in hydrochloric acid solution and determined by AAS. In this paper, the factors influencing the detection of gold by AAS were discussed, which include the setting of parameters of the instrument, the liner range and the interfering ions. The interference test indicated that other precious metals had no influence for gold determination. Under the selected instrument conditions, the gold in the standard samples was tested, and the result was in agreement with the standard value. The RSD (n=11) of gold was between 0.72%～5.49%, the recovery was between 98.82%～99.20% by detecting standard and certain mine gold ore sample. This method is stable, reliable and accurate which is suitable for the gold content from 0.X to XX.0 mg·g-1 in ore and extends the analysiscontent range for Au by FAAS. More importantly, it reduces the traditional fire assay on human and environmental damage and pollution. AAS has the advantages of fast response, high sensitivity and good accuracy which provides a technical basis for further research on the detection of other precious metals by this method.