In order to study the evaporation process and mechanism of Jatropha methyl ester-diesel blends which was added nanoparticles, the evaporation characteristics of different concentrations of NPs (0.05%, 0.5%, 2%) in Jatropha methyl ester-diesel blends (BD20) were studied by suspension droplet technology. The evaporation characteristics of these fuels at 873 K and 973 K were analyzed and compared. The evaporation process of different concentrations of NPs (0.05%, 0.5%, 2%) presented a stable performance without intense micro-explosion, and the evaporation stage was divided into two parts. The normalized square diameter of droplet fluctuated slightly during evaporation, and the equilibrium evaporation stage followed the law of D-2. The results showed that at high temperature, low concentration of NPs promoted the absorption of heat in the droplet, thus reducing the evaporation life of the droplet, while high concentration of NPs restrained droplet evaporation, thus increasing the evaporation life of the droplet.