In this paper,the emitting layer was fabricated with host and guest interlaced,t hat is,the emitt ing layer consisted of a periodic thin layer of host material of CBP separated by guest material of Ir(piq)₂(acac).In order to impr ove the performance of the device,the thicknesses of host layer and guest layer were optimized respectively.As a result,the optimal thickness of the single-host layer was 3~4nm,and the single-guest layer was 0.3nm,the maximum current efficiency of the device was 3.92cd/A.The colour purity and luminescence stability were both good,the OLEDs achieved stable red emission with a CIE coor dinate of (0.6695,0.3085) at an operation current of 1mA,and a small CIE variation value of (0.0042,0.0020) in the operation current range of 0.1mA to 1mA.This preparati on method with host and guest interlaced not only was simple in process,but also c ould adjust the thicknesses of host and guest layer separately,the influence of the aggregation of guest molecules or the long-ran ge dipole-dipole interaction on efficiency can be reduced.This method provides ideas for preparation of non-doped phosphorescent organic light-emitting diodes.