With the significant expansion of the breadth and depth of financial services for the real economy, the real sector's "be diverted out of the real economy" trend has become a structural contradiction, and the motivation and appropriateness behind the enterprise's financialization have become an urgent issue to be resolved. This paper starts from the enterprise's response to risk and uncertainty, as well as the financialization drive mechanism to pursue shareholder value, and constructs the optimization problem of the investment portfolio intending to minimize enterprise risk and maximize shareholder value, and then obtains the optimal allocation of financial assets under different objectives reflecting the relationship between enterprise risk, shareholder value and the non-linear relationship between the levels of enterprise financialization. On this basis, based on the fact that the enterprise's financialization driving mechanism reflects the characteristics of the financialization motivation, we start from the enterprise's asset allocation structure. Combined with the optimal allocation of financial assets under specific objectives, we propose the criteria for determining the enterprise's financialization motivation and the appropriate scope of the enterprise's financialization. Then, we selected the representative listed non-financial enterprises in China as a sample for empirical analysis:As for the identification of the motivation of financialization, this paper found that although the non-financial enterprise sector is still dominated by the "reservoir" motivation, the whole, the "investment substitution" motivation is more significant and cannot be ignored. There is heterogeneity among different industries and enterprises with different equity natures, among which the motivation of "investment substitution" in the wholesale and retail industry and real estate industry is significant, and the motivation of "investment substitution" in non-state-owned enterprises is significantly stronger than that in state-owned enterprises. Concerning the appropriateness of enterprise financialization, we find that the overall financialization appropriateness of the non-financial enterprise sector is low. Especially in the information technology industry and the power, gas, and water production and supply industry, the appropriateness of financialization is significantly lower than the average level, and the level of industry financialization is insufficient. In contrast, the wholesale, retail, and real estate industries have excessive financialization. The moderation of non-state-owned enterprises' financialization is significantly higher than that of state-owned enterprises, and there is also the phenomenon of excessive financialization. The conclusion of this paper provides guiding suggestions for financial investment decision-making and regulatory identification of enterprises.