Quick and nondestructive detection of seed vigor is a popular and difficult task in the seed research field. Based on the relationship between seed respiration and seed vigor, we proposed a rapid non-destructive testing system for seed vigor based on TDLAS technique. The proposed system comprises a distributed feedback laser and its control circuit, a photoelectric conversion and amplification circuit, a data acquisition circuit, an upper computer software, and a seed breathing carbon dioxide (CO2) concentration detection pool based on a multi-reflection pool structure. The detection pool has a volume of 1.5 L, a light path of 16 m, and a laser source band of 2004 nm. Based on Lambert Beer''s law, we use wavelength modulated absorption spectroscopy and second harmonic generation to invert the CO2 concentration generated during seed respiration. Seed vigor is determined according to the concentration of CO2 in seed respiration, and the vigor index obtained from the germination and seedling emergence experiment is compared and validated. The experimental results show that the correlation between the change of CO2 respiratory intensity and seed vigor grade index is greater than 0.9, i.e., the rapid non-destructive testing system for seed vigor based on TDLAS technique can accurately, nondestructively, and efficiently reflect the seed vigor grade. This study provides useful exploration in non-destructive testing and grading of seed vigor using TDLAS technique.