Loan investigation is the basis and key of credit management, and it is also an important basis for loan review, deliberation and approval decision. Account managers play an important role in loan investigation. This paper puts forward the following suggestions on how account managers do a good job in loan investigation. First, investigate the authenticity of customer assets and accurately judge the solvency of enterprises. First of all, investigate the authenticity of current assets and verify the current ratio, which is the main index reflecting the short-term solvency of enterprises. We should investigate from the following three aspects: First, investigate the authenticity and changes of accounts receivable. Mainly investigate accounts receivable. Whether the time limit and quota are reasonable; The change of the total amount of accounts receivable in recent years and whether it matches the increase or decrease ratio of enterprise sales; If the provision for bad debts is not mentioned, and many accounts receivable exceed the normal settlement period, it should be excluded when calculating the effective current assets of the enterprise. The second is to investigate the authenticity of other accounts receivable.