In a period of uncertainty about economic development, it is particularly important to maintain corporate sustainable growth in order to deal with the risk management challenge of sustainability. Private benefits of control in corporate governance play a crucial role in ensuring corporate financial sustainability to face the risk. The existing literature about private benefits of control mainly focuses on the assumption of absolute control by the ultimate controller, ignoring the influence of subsidiaries. This paper constructs a model of private benefits, based on a framework of the interaction of ultimate controllers and subsidiaries, and investigates how subsidiaries influence the ultimate controller’s expropriation. The model has proposed that: Subsidiary’s self-interest demand can prevent the ultimate controller’s private benefits; the autonomy owned by the subsidiary can be used to allocate resources, inhibiting the private benefits of control to some extent. Further research has found that when the proportion of funds that can be arranged by the subsidiary’s autonomy can meet the proportion of funds required for the subsidiary’s self-interest demand, as the subsidiary’s self-interest demand increases, the ultimate controller’s expropriation is reduced. This paper reveals the internal mechanism that private benefits of control are jointly determined by the ultimate controller and the subsidiary, expands the research on the decision mechanism of private benefits and provides new ideas for understanding the expropriation of the ultimate controller. Additionally, the solution to this problem can provide help and inspiration for risk management challenges for the sustainability of the corporate, as well as provide reference significance for economic sustainability.