A novel energetic material, 1-amino-1-(2,4-dinitrophenylhydrazinyl)-2,2-dinitroethylene (APHDNE), was synthesized by the reaction of 1,1-diamino-2,2-dinitroethylene (FOX-7) and 2,4-dinitrophenylhydrazine in N-methyl pyrrolidone (NMP) at 110 $^{circ}C$. The theoretical investigation on APHDNE was curried out by B3LYP/6-311+$G^*$ method. The IR frequencies analysis and NMR chemical shifts were performed and compared with the experimental results. The thermal behavior of APHDNE was studied by DSC and TG/DTG methods, and can be divided into two crystal phase transition processes and three exothermic decomposition processes. The enthalpy, apparent activation energy and pre-exponential factor of the first exothermic decomposition reaction were obtained as -525.3 kJ $mol^{-1}$, 276.85 kJ $mol^{-1}$ and $10^{26.22}s^{-1}$, respectively. The critical temperature of thermal explosion of APHDNE is 237.7 $^{circ}C$. The specific heat capacity of APHDNE was determined with micro-DSC method and theoretical calculation method, and the molar heat capacity is 363.67 J $mol^{-1}K^{-1}$ at 298.15 K. The adiabatic time-to-explosion of APHDNE was also calculated to be a certain value between 253.2-309.4 s. APHDNE has higher thermal stability than FOX-7.