Three-dimensional dicing machine has some advantages of high efficiency, compact structure and not easy to be clogged. However, there is always uneven phenomenon on the diced section, especially when cutting big side block. In order to improve the quality of dice, analyzed the mechanism of three-dimensional dicing, established the curve equation of inclined section of fruits and vegetables block, analyzed the main affecting factors of the quality of diced section and divided diced sections into three shapes of right deviation, left deviation and symmetrical. Using relative deviation and gradient of the section as evaluation index to analyze the effects of center spacing and speed ratio between the strip cutting knife pivot and centrifugal cutting tumbling barrel on quality indicators of section.The date of two-factor variance analysis showed that the weight relations between the deviation and gradient of the section when cutting big side block. The result can provide the basis for dicing machine parameter optimization.