The tensile strength of an anchor system buried under the surface of the seabed mud increases gradually with the increase of backfill strength. In order to guarantee the safety of ship’s mooring, it is necessary to determine the tensile capacity growth of anchor system in the pit backfill. Using the calculating method of ABAQUS finite element software, we study the quantitative relationships between them combining with engineering examples.Adopting the temperature-controlling parameters’ reduction method and “three-step calculation” thinking, we obtain the formulae for the relationship between the two. With the actual strength of the backfill and undisturbed soil, we can calculate the tensile strength of the anchor system in a given period.