To enhance the efficiency of cathode electron injection of organic light-emitting diode (OLEDs), we designed a new hybrid modified layer (HML) with the structure of Bphen: LiF/Al/MoO3, which was applied to ITO/NPB/Alq3/Al. The traditional material LiF is used for the electron injection layer of the reference device. The results show that using HBL at the interface between organic and cathode is very effective. We have measured the electroluminescence (EL) spectra of the device. The EL peak of the device is 534 nm, which indicates that it is from Alq3. It can be seen that the structure design of the multilayer modified layer does not change the luminescence spectrum of the device. Bright green emission can be obtained from the optimized EL devices. Compared with traditional device based on LiF, the performance of the single unit with hybrid modification layer has better luminous properties and efficiency. Present research work shows that when the optimum parameter of the hybrid layer is Bphen∶LiF(5 nm; 6%)/Al(1nm)/MoO3(5 nm), the maximum current efficiency and the maximum power efficiency of the device are 4.28 cd·A-1 and 2.19 lm·W-1, respectively, which are 25.5% and 23.7% higher than those of the reference device. Current-voltage characteristics demonstrate that the hybrid interfacial layer can promote electron injection, thus increasing the current efficiency and reduced their operating voltage slightly of OLED. We systematically analyze the improvement of device performance from two aspects. On the one hand, LiF can fill the electron trap of Bphen to enhance the current injection, moreover, HML can also block hole transport and reduce the hole current. On the other hand, based on charge balance factor theory, HML enhances the injection of electrons and increases the charge balance factor, which improves the balance of carriers in the device. The experimental results show that the cathode hybrid layer can improve the performance of the device.