The 3rd National Soil Survey is of great significance. In order to ensurethe authenticity and reliability of thedata， the standard detection methods need to be repeatedly verified to optimize the method suitable for nationwide promotion. Due to poor linearity of the standard curve of turbidimetric method in NY/T 1121.14—2006 todetect soil availablesulfur，it is urgent to optimize the extraction and determination conditions to improve the accuracy and precision of the method. In viewofthis，it was explored the influence of the state and brand of precipitator and the method of linear fitting on the linearity of the standard curveof the turbidity method in the paper. The result showed that the correlationcoefficient( r)of the standard curve can be >0.999 and meet the requirements of analysis if the freshly prepared 40 g/L BaCl2 is used. At the sametime，the determination of soil available sulfur by inductively coupled plasmaspectroscopy(ICP -OES)was verified and compared. The detection limits of turbidimetric method and ICP-OES were 1.20 and 0.80mg/kg，respectively，which satisfied the requirements of analysis and test. The results of accuracy and precision verification showed that turbidimetric method and ICP-OES could be used for the detection of soil available sulfur and there was no significant difference in the results. The turbidimetric method was suitable for the determination the samples with concentration below48 mg/kg，and the ICP-OES was better to the samples ranging of 0-150 mg/kg samples. Based on the experience in detection of 3rd National Soil Survey pilotwork，it was suggested that ICP-OES should be as the standard method for the determination of soil availablesulfur， which could provide reference for the 3rd National Soil Survey.