The accurate content of boron directly restricts the boron isotope determination by using Positive Thermal Ionization Mass spectrometry based on Cs2BO+2 ion. At present, there is a big problem in determination of high salt and low boron samples with Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), mainly in two aspects: high salt matrix interference and instrument detection limit, and simple dilution can not solve these difficulties very well. At present, the above two problems will be encountered when determining the boron content in the salt samples by ICP-OES, therefore, it is necessary to enrich boron and remove the matrix ions. In this paper, Amberlite IRA 743 boron-specific resin is applied to purify the boron element, and the high-salt matrix can be removed, but there are some sodium ions adsorbing at the same time. Using 3 mol·L-1 NH3·H2O can remove most of the adsorbed sodium ions and have no effect on the adsorbed boron. Then eluting boron from the resin with10 mL 0.1 mol·L-1 HCl at 75 ℃. 208.900 nm was chosen as the detection wavelength for boron, and the recoveries were in the range of 106.00%～108.40%; the detection identification and quantification limits are 0.006 and 0.02 mol·L-1, respectively. Through the 12 times repeated experiments under different salinities, the relative standard deviations range from 1.94% to 3.37%, which less than 5%, so we think the method is feasible, and there is no accidental error. Combining with this method and Positive Thermal Ionization Mass spectrometry based on Cs2BO+2ion, the deternination of the boron content and isotopic composition of eight salt samples are achieved.