A new host material BCz-Si for blue and white phosphorescent organic light-emitting devices was designed and synthesized. The introduction of triphenylsilyl moiety on BCz unit can efficiently tune the HOMO/ LUMO energy levels and maintain high triplet energy. Its carrier mobility, thermal, photophysical, and electrochemical properties were also systematically investigated. The high triplet energy of BCz-Si ensures efficient energy transfer from the host to the triplet emitter Firpic. The blue device using BCz-Si as a host material achieved a maximum quantum efficiency of 21.0%, corresponding to a current efficiency and power efficiency as high as 46.5 cd/A and 45.8 lm/W, respectively; Meanwhile high efficiency white phosphorescent OLEDs hosted by BCz-Si were also fabricated with a maximum external quantum efficiency 24.6%, 70.5 cd/A for two-color based and 21.5%, 50.1 cd/A for three color based devices.