As a very important Resolution Enhancement Technology (RETs),Off-axis Illumination (OAI) is widely applied to optical projection lithography system.Application of Diffractive Optical Element(DOE) to OAI not only can cotrol precisely the flexible illumination shape and the intensity profile but also can retain a higher efficiency of light source.In this paper,the four kinds of DOEs with 8 phase levels were designed by using the step-iterative algorithm based Fourier transfer,and the four elements could realize dipole,quadrupole,annular and Bulls-Eye illuminations respectively.The simulation results show that the efficiencies of the light sources are all better than 80% and the RootMean-Squares(RMSs) of intensity profiles are all smaller than 7% as compared with that of the ideal one.