In order to explore the reasonable scheme of combined application of modifier and biogas slurry and realize the improvement of saline-alkali land，this experiment aimed at saline-alkali land in Da’anCity，JilinProvince，and studied the improvement effect of combined application of biogas slurry and modifier on soda saline-alkali soil through fieldexperiment. The results showed that the combined application of amendments and biogas slurry effectively increased the content of soil organicmatter，available phosphorus，available potassium and alkali -hydrolyzablenitrogen，increased the total porosity and the number ofsoil aggregates，improved the stability ofsoil aggregates，significantly increased thericeyield，and effectively reduced soilpH，soil bulkdensity，alkalinity and water-soluble saltcontent.Comprehensive analysis showed that the combined application of desulfurized gypsum and biogas slurry had the best effect on the improvement of soda saline-alkalisoil. Compared with the treatment without biogasslurry，the content of organic matter was increasedby100%，the content of available phosphorus wasincreased by34%，the content of available potassium wasincreased by59%，the content of alkali -hydrolyzable nitrogen wasincreased by104%，the total porosity wasincreased by14%，the number of soil aggregates wasincreased significantly，and the stability of soil aggregates wassignificantlyimproved；The yield increase rate was76.77%， the soil pH wasdecreased by12%，the soil bulk density wasdecreased by9.9%，the alkalinity wasdecreased by11%，and the water-soluble salt content was decreased by 48%.