1. Strengthen the supervision and standardization of internal audit services. Internal audit outsourcing belongs to a new business field. The Institute of Certified Public Accountants should bring the internal audit business of accounting firms into its unified management and guidance, standardize the competition order of internal audit business, and formulate corresponding guidance norms, so that the internal audit business will develop in the right direction from the date of its birth. At the same time, we should improve the corresponding laws and regulations and make clear provisions on the independence and other related issues caused by the provision of internal audit services by accounting firms.

2. Popularize the International Certified Internal Auditor (CIA) exam. There are great differences between internal audit and external audit in audit scope, audit focus, work depth and function. Certified public accountants can be competent for external audit, but not necessarily for internal audit. Certified International Auditor (CIA) is the symbol of an expert in the field of international internal audit and the only professional qualification in the world. But at present, there are not many certified public accountants who have obtained this qualification in China. Therefore, it is necessary to vigorously promote CLA examination, so that more certified public accountants can provide high-quality internal audit services for enterprises.

3. Enterprises should choose the appropriate outsourcing form according to the situation. For large and medium-sized state-owned enterprises, on the one hand, the internal audit department is set up in accordance with the provisions of the National Audit Office, on the other hand, the complete outsourcing of internal audit functions will have many sequelae. Therefore, outsourcing some internal audit functions will be a wise choice. Enterprises should set up internal audit departments, equipped with internal auditors who are familiar with the situation of enterprises and have strong business ability. And according to the needs of enterprises, hire certified public accountants or other professionals to cooperate with internal auditors to carry out internal audit work.

For small and medium-sized enterprises, there are not many internal audit tasks, so it is not worth the candle to set up an internal audit department and equip internal auditors. At this point, outsourcing all internal audit functions may be the best choice for enterprises.

4. Accounting firms should establish a strict risk control system. As the main provider of internal audit outsourcing services, accounting firms should establish a strict risk control system and make clear provisions on the business undertaking, staffing, business development, liability limitation and remuneration of internal audit services, so as to reduce the risks of the firms and provide high-quality internal audit services to customers in a timely manner.