To meet the demand of film capacitors in harsh condition applications, research workers devote their effort to develop high temperature resistant polymer dielectrics with high energy density. In this paper, a new type of dipole glass polymer, polynorbornene containing cyano-group side chain (PDMBN) is prepared by ring opening metathesis polymerization. The high dipole moment of the cyano-group possesses high polarization, resulting in that the discharge energy density (Ud) of 8.6 J/cm3 and efficiency of 84 % are found in the PDMBN at room temperature. Via using three organic semiconductors with increased electron affinity (NBTI, NBTI-SO2 and NBTI-2SO2) as the fillers, the energy storage properties of PDMBN matrix are further improved due to the binding effect of free electrons. In addition, the interfacial barrier height is inversely proportional to the temperature, electric field and electron affinity of fillers. As a result, 0.7- wt% NBTI-SO2/PDMBN achieves a maximal Ud of 11.6 J/cm3 at 600 MV/m and room temperature. At elevated temperatures, the conduction loss of polymer PDMBN increases sharply, causing a rapid decline in energy storage performance. Nevertheless, the maximum Ud of 0.7-wt%NBTI/PDMBN composite film at 100 °C and 150 °C can reach 6.2 J/cm3 and 4.5 J/cm3, respectively. This study is helpful for the design of polynorbornene dielectrics, and provides an important reference for the construction of carrier traps in polymer dielectrics at high temperature.