Physical property indexes of coastal saline soil and improved coastal saline soil such as specific gravity,plastic limit,liquid limit,plastic index,maximum dry density,optimal water content were studied through laboratory experiments in this paper. Based on unconfined compressive strength test,the unconfined compressive strength of improved saline soils at the curing age of 7 d,14 d,28 d and 60 d were studied. Taking the improved saline soil samples at the curing age of 14d as an example,the stability of the improved saline soil under different soaking time (1 d,4 d,7 d,14d) was studied. The test results show that some indexes such as specific gravity,liquid limit,plasticity index and maximum dry density decrease linearly with the increase of the total content of the admixture;other indexes such as plastic limit and optimal water content increase linearly with the increase of the total amount of admixture. The unconfined compressive strength of improved saline soil increases with the increase of curing age and total admixture content. The unconfined compressive strength of improved saline soil decreases with the increases of immersion time. The unconfined compressive strength of improved saline soil increases linearly with the increase of the total amount of admixture. The water stability coefficient of each ratio increases with the increase of curing age. With the increase of the total amount of admixture,the stability coefficient of unconfined compressive water of improved saline soil basically increases linearly. With the increase of soaking time,the range of mass loss rate becomes larger and larger. With the increase of the total amount of admixture,the loss rate of modified saline soil basically decreases as a power function.