According to Baidu Encyclopedia, there are many reasons for the shipping company to change the bill fee. First, liner companies actively reduced the capacity, and then empty containers could not be transported back to the port, which made it difficult to find containers, and then the efficiency of port operations decreased. Fourth, the crew epidemic limited the effective delivery of ships. Fifth, various emergencies further reduced the efficiency of ship operations. Sixth, the demand for container transportation in international trade began to rise. Finally, the sales model of container liner shipping space contributed to the situation. The above seven aspects are promoted layer by layer. Any unilateral targeted measures may have little effect on curbing the increase in freight rates.