A method for preparing an extruded nylon elastomer in a twin-screw reactor. A hydroxyl-terminated nylon oligomer is prepared, then the oligomer is mixed with an isocyanate and a polyether polyol, and the elastomer is produced using a twin-screw one-step mass polymerization process. Batch production of the prior art is transformed to continuous automated controlled production, whereby annual output of a single line can be increased 3-5 fold, and labor costs reduced 1-3 fold, with improved product quality and stability of batch production processes.