Abstract: In recent years, China's domestic economic aggregate has grown steadily, and the market competition has become increasingly fierce. Therefore, internal control has become an important part of the future survival of enterprises and the key to sustainable development. A sound internal control system must be reasonable in theory and feasible in practice. Therefore, based on the five elements of the internal control framework, combined with the actual needs of enterprise management, this paper designs the internal control of four economic operation cycles: monetary funds, procurement and payment, sales and collection, and cost. Finally, the paper analyzes the problems existing in China's internal control system, and puts forward opinions and suggestions from three aspects: perfecting the internal control structure, strengthening budget management and giving full play to the internal audit function.

Key words: internal control, monetary fund, purchase and payment. Sales and collection, cost, internal audit