The work aims to improve the efficiency and accuracy through the process of size design for corrugated boxes, and shorten the development cycle of the product. With the size calculation as the main clue, the optimizing system for the size design of corrugated box from the arrangement optimizing of inner content to the calculation of the stacking layers and stacking height finally with PHP programming language and Mysql database was designed. This optimizing system could reduce the computed amount and the time for analysis and comparison in the process of size design, and improve the work efficiency greatly. This system has certain practical value, but some problems still exist, such as the safety coefficient of stacking strength to be determined by experience and the lacking of prediction of anti-drop capability and cushioning property. This system still needs to be improved.