Organic light emitting diode (OLED) devices possess the characteristic s of light weight,low power consumption,high response speed and flexibility.They have shown the grea t superiority in the flat panel display and solid-state lighting.In order to enhance the performanc e of OLED devices,the Expert OLED software was used to simulate the actual OLED devices with different grating structures. The electroluminescent (EL) spectrum,the luminous angle and the electric field distribution were analyzed in the OLED devices with bimetal electrodes.The optimized micro/nano grating structures was obtained.And for OLEDs with different grating periods,the varied grating h eight has different effects on the luminescence performance.We can also improve the luminescence pe rformance by adjusting the molecular dipole orientation of emitting layer and optimizing the electric field distribution in the OLEDs.This work provides a valuable reference on improving the performan ce of OLEDs by using the optimized periodic micro/nano grating structures.