The present invention discloses a polyamide resin and its application and polyamide composition thereof. The repeating units of the described polyamide resin comprises the following components: dicarboxylic acid units composed 80-100mol% of polyamide resin; aliphatic diamines units having 2-14 carbon atoms composed 80-100mol% of polyamide resin; lactam or amino acid units having 6-14 carbon atoms composed 0-20mol% of polyamide resin; in the described polyamide resin, the bio-based carbon concentration is more than 45%; the described bio-based carbon mole concentration is calculated according to the formula below: bio-based carbon concentration=(bio-based carbon mole content/total organic carbon mole content)*100%. The described polyamide resin in the present invention has low gas volatile, hence the polyamide composition produced thereof has low gas volatile too, and can be applied to food-contact field. In addition, the surface condition after reflow soldering of the polyamide composition produced is good.