Because it is difficult to observe willingness to repay debt, quantitative research is very few. Related party transactions provide a possible way for the enterprise group parent company occupied the interests of minority shareholders and creditors, and become a major means of instruction. However, because of information asymmetry, resulting in that a direct evaluation motivation and the underlying factors of related party transactions is difficult. The existing research has focused on qualitative analysis, the lack of quantitative empirical analysis. Based on a structured model can be used to describe the potential variable that cannot be direct observed, this paper establishes the structural equation model of willingness to repay debt of enterprise group parent companies based on preferences related party transactions and the financial situation of unusual perspective. Empirical analysis shows that the model can achieve good fitting results, then can use the financial ratios, related party transaction information, financial condition and other information to measure willingness to repay debt, which provide a reference point for the quantitative analysis of related party transaction, and can help to improve the assessment of credit risk of enterprise group.