Abstract: The present disclosure is related to the field of polymer materials, and, in particular, to a method for synthesizing a bio-based polyamide. More specifically, the disclosure provides a method for synthesizing a block copolymer consisting of a hard segment of a polyamide prepared via solid state polycondensation and a soft segment of a polyether polyol. Due to a reaction of itaconic acid, which contains a carbon-carbon double bond, with hexamethylenediamine, the bio-based polyamide is greatly different from conventional linear polyamides and exhibits a lower glass transition temperature and excellent mechanical properties. Unlike conventional processes for preparing modified polyamides, the bio-based polyamide is synthesized, according to the method, through chain extension of a polyamide with an excess amount of a diisocyanate based on amine value of the polyamide and then crosslinking of the resulting product with a polyether polyol by using glycerol as a crosslinking agent.