The cash flow statement can provide cash flow information of an enterprise, so as to objectively evaluate the overall financial status of the enterprise. Through the cash flow statement, investors and creditors can make a more reliable judgment on the enterprise's ability to pay and repay debts and the enterprise's demand for external funds. Through cash flow, we can not only know the current financial status of the enterprise, but also predict the future development of the enterprise. Cash flow chart is a graph describing cash flow as a function of time, which can show the inflow and outflow of funds at different time points. It is an effective tool for economic analysis, and it is as important as the structural mechanical diagram in mechanical calculation.