Abstract：The development of rail industry's diversifying economy presents new requirements to its internal audit and new tasks for audit staff, such as how to adjust new working thought, innovate more and improve the quality of audit work.Based on audit staff's practical experience, this paper proposes that the capital flow in audit work be attached more importance so as to control company's business transactions and operation process, investigate and punish those who violates rules, promote company's better economic performance, ensure fund security, and reduce company's operation risk.

Keyword：internal audit;capital flow;multi-business company;