Aiming at the problem that calculating the crack width after the high-strength reinforcement is used in the concrete flexural member of port and waterway engineering，we analyze the crack width calculation formulas of various professional concrete specifications in China，and obtain that the crack width calculation results are the largest in the port and waterway engineering specification. Although we use high-strength reinforcement in the design，the amount of reinforcement is basically the same，which limits its strength and is not conducive to the promotion. According to similar statistical formulas of other researchers，we propose a crack width correction formula suitable for port and waterway engineering，and verify it by comparison.The results show that the formula in this paper is in good agreement with other formulas and can be used for references in the revision of the specification.