The salt-containing characteristics of soft soil are an important indicator of foundation design, and salt-containing features are mainly protected by deposition environment, often with strong geographicalism. In the Changjiang River Ekimae, the softener of the Changjiang River Ekimae is a research object, collecting multi-sets of soil samples for indoor trials, and conducts salt-containing characteristics, parameter correlation and deposition environment analysis. The results show that the salt-containing salt is NaCl type, the salt content is 0.613%, mainly based on weak saline soil, accounting for 85.4%. The salt content, Cl⁻ content, Na⁺ content, K⁺ content peak test meets the regular distribution, but the reputation test value is located in the rejection domain, and does not belong to normal distribution. Other ion assumptions and peak tests do not comply with the right to distribution. The salt content of soft soil is highest in relationship with Cl⁻content, and is good to ion-relevance to the Ca²⁺ content and ${\rm{CO}}_3^{2-} $. The content of the soil-solvent Cl⁻ content and salt content, the ${\rm{SO}}_4^{2-} $ content is equipped with the highest multiplication effect; Cl⁻ content is best fitted with Na⁺, Ca²⁺, Mg²⁺, K⁺, ${\rm{HCO}}_3^- $ contents fitted to polynomial fitting effect. The soft soil is deposited by an alkaline environment. The sodium adsorption ratio of soft soil is 54.35, which is close to the sodium adsorption ratio of seawater, indicating that the salt-containing characteristics retains the seawater characteristics, and with the increase of depth, soft soil sodium adsorption ratio has reduced trend. The soft soil formation time is related, the older the formation of soft soil, the longer the time of penetration. The Sr/ Ba value of the soft soil is much greater than 1, indicating that the soil deposition environment is a marine environment. The γ_Mg/γ_Ca value in the soft soil leaching solution is much higher than the γ_Mg/γ_Ca background value, which is subjected to seawater dipping. The seawater mixing model is introduced, and the seawater mixing ratio is calculated. The low value of the seawater mixing ratio is mainly distributed in the west far away from the coast, and the soil deposition in this area is mainly controlled by the water of the Changjiang River. The high value of seawater mixing ratio is mainly distributed in coastal areas, where soil deposits are mainly controlled by transgression, and the marine facies attributes are heavier.