Abstract: Characteristics and inadequateness of present score functions in the vague set theory are analyzed, and main factors of score functions are discussed. From the perspective of risk aversion and considering the effect of uncertainty degree, the concept of vague value expectation is proposed and a risk aversion type score function constructed based on it. The character of the new score function is discussed and an example is given showing that it can reflect the decision-making preferences and maintain the consistency of the decision-making method.