According to the characteristics of various indicators in the financial appraisal system of construction companies, all the weights of indexes were calculated by the improved entropy method based on entropy theory. Meanwhile, the grey correlation degrees between the evaluated object and the optimal parameter values were calculated by applying the grey relational analysis. And then the entropy weights of all the indexes were combined to calculate the evaluating value and ranked, in which the investors, the enterprise managers, and the market regulators will make their decisions due to the scientific analysis of the financial appraisal in these construction companies. Finally, it revealed the running situations in financial status of the construction companies by analyzing the financial statements of fifteen construction companies in the market with the previous method.