The sugar beet variety KWS 1176 was used as the experimental material and a plot experiment was conducted on the saline alkali soil（Na⁺ content 203.33 mg·kg^-1 ，pH 8.92）in Wujian Village，Shangjia Town，Zhaodong City， Heilongjiang Province. Four treatments were set up in the experiment，including without the addition of wood vinegar （CK），300 kg·hm^-2 of wood vinegar（BW1），600 kg·hm^-2 of wood vinegar（BW2）and 900 kg·hm^-2 of wood vinegar （BW3），each treatment was treated with biochar at a dosage of 600 kg·hm^-2 . Results showed that the combination of wood vinegar and biochar significantly increased soil specific surface area（1.39%-4.86%）and water content，while reduced soil pH and electrical conductivity，significantly increased the content of soil nutrients（alkali hydrolyzed nitrogen，available phosphorus，and organic matter）in the current season. The effect of soil nutrient improvement was significant at 58 days after sowing，with alkali hydrolyzed nitrogen，available phosphorus，and organic matter increasing by 14.24%-26.87%， 21.17%-32.09% and 2.51%-41.19%，respectively. The content of Ca²⁺，Mg²⁺，SO₄ ^2- and Cl^- in the soil treated with BW2 were significantly increased，while the content of soluble Na⁺ and HCO₃ ^- were significantly decreased；BW2 significantly improved the yield and quality of sugar beet root tubers，reduced the sodium，potassium and α-amino nitrogen content in the root tubers. Compared with CK，the content of amino nitrogen in root tubers was increased by 5.32%-15.29%，and the sugar content in root tubers was increased by 0.31%-0.84%. Overall analysis showed that BW2 had the best effect on improving the physicochemical properties of saline alkali soil during the season，as well as the yield and quality of sugar beet root tubers.