The invention provides a polyamide 56 material prepared from bio-based 1,5-pentamethylene diamine. The polyamide 56 material is renewable and has the high flame-retardant property. The polyamide 56 material comprises polyamide 56 and a composition of nitrogen-containing flame retardants or is a polymer formed by pentamethylene diamine, adipic acid and nitrogen-containing flame retardants serving as a polymeric monomer. The material is good in flame-retardant effect, low in toxicity, high in safety, low in cost and capable of being used as engineering plastics and a spinning material. According to the material, the preparation process is simple and convenient, and wide industrial application prospects are achieved.