In order to study the plasticizing properties of new energetic plasticizer (2,2-dinitropyl)-2-hexyl decanoate (A16) with Hydroyl-Terminated Polybutadiene (HTPB), the compatibility of them was simulated by molecular dynamics method. The apparent viscosities and mechanical properties of HTPB/A16 and HTPB/DOS systems at different plasticizing ratios and temperatures were studied and compared. The interaction between HTPB and A16 was dominated by Van der Waals force. The difference between the solubility parameters of HTPB and A16 was only 0.004 (J·cm^-3)^1/2, indicating good compatibility. The apparent viscosity of HTPB/A16 system was higher than that of HTPB/DOS system. With the increasing plasticier mass ratio or temperature, the difference between the two systems decreased. When the plasticizing ratio was 1∶1 and the temperature was 70 ℃, the viscosity of HTPB/A16 was only 60.5 cp higher than that of HTPB/DOS, suggesting equivalent reduction effect of A16 and DOS. Under the same plasticizing ratio, both the tensile strength and elongation of HTPB/A16 system were larger than that of HTPB/DOS system. When the plasticizing ratio was 1∶1, the elongation at break of HTPB/A16 was 18.6% higher than that of HTPB/DOS, whereas the modulus was 8.6% lower.