The variation of the environmental factors of marine soft soil in industry zones of Qinzhou Port and Fangcheng Port was analyzed. The soil soaking load linkage is a self-developed device for mechanism simulation, used to examine the environmental factors of marine soft soil when the thickness of coastal reclamation layer and concentration of chemical constituents of pore water ions changed. The soft soil samples were obtained artificially. Direct shear tests of threse artificial soft soil samples were carried out. The test results showed that cohesive force c and internal friction angle φ of artificial soft soil samples changed with calcium ion larger than magnesium ion when concentration of calcium ion or magnesium ion increased. There is certain coupling effect between the additional load stress of coastal reclamation layer and ion concentration of soak liquid for the shear strength indexes of the soil. However, the coupling effect of cohesive force is obvious while that of internal friction angle is less significant.