Abstract: DES-lignin was extracted from pine feedstock by using deep eutectic solvents(DES) at treatment temperatures of 100, 130, and 150 ℃, and the resultant DES-lignin samples with nano scale were labeled as L₁₀₀, L₁₃₀, and L₁₅₀, respectively. The yields and elemental compositions of DES-lignin were determined, and the thermal degradation characteristics of nanoscale DES-lignin were studied by fast pyrolysis and thermogravimetric analysis(TGA). The results showed that the yields of L₁₀₀, L₁₃₀ and L₁₅₀ were 33.53%, 81.02% and 82.62%, respectively, along with lower H/C molar ratio. DES treatment temperatures of pine wood had significant effect on the thermal degradation properties of lignin nanoparticles. With the increment of DES treatment temperature, the yields of biochar derived from DES-lignin pyrolysis gradually increased, and biochar obtained by fast pyrolysis at 700 ℃ had great high calorific value(30.97-31.96 MJ/kg) and homogeneous mesoporous. Besides, TG analysis indicated that the intense pyrolysis reaction of DES-lignin took place mainly ranged from the temperature of 200 to 500 ℃, the peak temperatures of the maximum weight loss rate occurred around 265 and 385 ℃, respectively. In addition, non-isothermal Coats-Redfern integration method was used to fit the reaction kinetics of DES-lignin pyrolysis, which demonstrated that DES-lignin pyrolysis was a secondary kinetic reaction in the main reaction temperature zone(200-450 ℃), and the obtained activation energy of L₁₀₀, L₁₃₀ and L₁₅₀ pyrolysis ranged 51.52-52.13 kJ/mol during temperature from 200 to 300 ℃ as well as 32.65-49.25 kJ/mol during temperature from 330 to 450 ℃.