With the development of marine economy industries, huge quantity of sewage with only preliminary treatment is disposed into the nearby coastal areas and has deteriorated the water quality of the near coastal region. Seawater quality has received increasing scientific attention. Seawater environment quality evaluation is the process of analyzing combinations of certain evaluation indexes and evaluation criteria with the uncertain valuation factors and changes in their content, which is a complicated and uncertain system with coupled multifactor and multilevel effects. In this paper, the variable fuzzy model method is introduced for the comprehensive evaluation of seawater environment quality,a seawater environment quality assessment model based on multi-objective variable fuzzy set theory (VFEM)was developed. The water quality status of Laizhou Bay of China was quantitatively studied, the results indicated that VFEM is a promising tool for evaluating the seawater quality status,which can perform well and accurately evaluate the comprehensive status of the seawater environment quality through the change of variable model parameters (a, p),combining the linear models and nonlinear models, taking the stable result as the final evaluation of the seawater quality,and determine the level of water quality evaluation. Therefore, the evaluation result is more reliable than other modeled results. In addition, the assessment model of seawater environment quality based on multi-objective variable fuzzy set theory can accurately classify the water quality of the sampling points to rank the water quality grade of every sampling point more precisely. This approach can also provide new concepts and means of improving and perfecting the study of seawater environment quality evaluations.