The core of the 200kg $r $n $r $n composite plant extract dry granulation machine lies in an innovative adjustment and locking mechanism. This device achieves precise, reverse, and synchronous adjustment of the distance between two extrusion wheels through a gear rack transmission system integrated on the side of the body. When operating, simply rotate the gear to make the two racks connected to the extrusion wheel shaft move in opposite directions and equidistant, thereby efficiently and symmetrically changing the clearance between the extrusion wheels. This can be used to produce particles of different sizes and also provides convenience for equipment cleaning. After the adjustment is completed, the unique locking mechanism securely fastens the moving parts through screws