The color rendering index (CRI) is an important evaluation parameter of white organic light-emitting diodes (WOLEDs). We fabricated a series of devices by vacuum evaporation to obtain WOLEDs with high CRI. The exciplex formed by NPB∶TPBi(1∶1) as a blue emission layer can reduce the difficulty and cost of fabrication of WOLEDs. Comparing this to a device with an exciplex emitting layer (3 nm), the device with the double-exciplex emitting layers (1.5 nm×2) helps to balance the exciton distribution and improves the CRI. Furthermore, the thickness of the spacer is changed to adjust the Dexter energy transmission of the exciton. When the thickness of the spacer layer 1 (Spacer 1) is 2 nm, the maximum power efficiency of the warm white light device B2 is 16.11 lm/W, the CRI is as high as 95 under a driving voltage of 5 V, and its correlated color temperature is 2322 K.