Abstract: The mutual guarantee behavior of private enterprises is more and more common in the capital market,but there are few guarantees specifically for private enterprises involved in financial fraud in academia,and it has certain theoretical and practical value to study it. By taking the crisis event of private enterprise Shandong Shengtong maintaining external guarantee while committing financial fraud as a case,it's found that thisenterprise used the mutually beneficial relationship in the guarantee circle to form a "protective umbrella" effect on it,resulting in information asymmetry inside and outside the enterprise. Information asymmetry in the guarantee circle would provide soil for enterprises to carry out negative behaviors,and enterprises could use the guarantee relationship to aggravate the degree of information asymmetry. Through the study of the case,it analyzed the governance problems and regulatory loopholes,and it also put forward the corresponding suggestions for improvement.