The nano heterojunction light emitting diode (LED) with structure of indium oxide (ITO)/ZnO/nanoporous Si pillar array(NSPA)/Si/Al is designed and fabricated, and the near white light electroluminescence (EL) is realized. Firstly, the NSPA layer is prepared on the surface of P-Si by using the vapor etching technique. Then, the surface of the NSPA is passivated by oxygen plasma and the luminescent properties of NSPA silicon substrate are improved by optimizing the passivation parameters. Finally, N type ZnO thin film is grown on the NSPA surface, and ZnO/NSPA nano heterojunction light emitting diodes are developed. The experimental results show that the oxygen plasma passivation treatment can effectively improve the light intensity of the device and realize an emission of near white light.