To explore the combination of microwave pre-processing with Inductively coupled plasma emission spectrometry （ICP-OES）in the detection of soil available boron，the digestion time，digestion temperature，temperature rise time， ferrum（Fe）co-existing interference elements and soil pH in the determination process were studied. Under the optimum working conditions of ICP-OES spectrometer，the spectral line boron（B）249.773 nm had high sensitivity and good peak shape. The results showed that the detection limit was 0.005 mg/kg when the sample weight was 10.00 g and the volume of extraction was 20 mL，the lower limit of determination was 0.020 mg/kg，and the precision and accuracy could meet the detection requirements. This method is suitable for the determination of available boron in batch soil.