The invention relates to a compression extruding 
host machine for a formed plastic environment-friendly recovering and granulating 
machine set, which is characterized in that the compression extruding 
host machine consists of a primary compression extruding part and a secondary compression extruding part, wherein the primary compression extruding part is a semi-fluid state formed by melting formed 
plastic materials and exhausting air; and the secondary compression extruding part performs secondary exhausting 
extrusion. The depth of a spiral groove of a main extruding spiral rod in the primary compression extruding part is 1 / 3 of the 
diameter, the thread 
pitch is 0.75 to 1 time of the 
diameter, and the 1 / 4 to 1 / 3 circle of the front end part is provided with head symmetrical extruding screws. The inside of a main material 
barrel discharge plate is provided with an inclined surface with conicity, the front side of the main material 
barrel discharge plate is provided with a plurality of small holes which are distributed according to an inverted equilateral triangle, and the outer side face of the small holes of the main material 
barrel discharge plate is provided with protection steps. The compression extruding 
host machine adopts a closed circular 
material supply system, improves the environment-friendly regeneration 
utilization rate, ensures that the light formed 
plastic materials are compressed and extruded at a high speed, improves the extruding and granulating efficiency and the 
operability, and ensures that the manufactured granules are uniform in size, full and glossy.