The invention provides a mixing cutter of a food processor. The cutter comprises a cutter shaft, wherein an upper cutter blade layer and a lower cutter blade layer are arranged on the cutter shaft in a staggered manner and are arranged on cutter blade fixing seats; and the cutter blade fixing seats are detachably connected with the cutter shaft through a fastening structure; the upper cutter blade layer or the lower cutter blade layer respectively comprises a first blade and a second blade which are parallel to each other and are rotationally symmetric; and the upper cutter blade layer and the lower cutter blade layer are staggered with each other at a certain angle in the horizontal direction. In the invention, by arranging the cutter blade fixing seats and the corresponding cutter blades, each cutter blade layer is equipped with two blades which are parallel to each other and are rotationally symmetric so that four blades at the upper and lower parts form a staggered space, thus ensuring that the food cut within a short time is more exquisite and more uniform; and the cutter blade fixing seats are connected with the cutter shaft through the fastening structure, can be mounted onthe cutter shaft conveniently and quickly and can be dismantled and washed freely, and one cutter blade layer or two cutter blade layers can be selected as required. The mixing cutter has simple manufacturing process, and is convenient in installation.