Bipolar host materials with high triplet energy are of great significance for highly efficient blue organic light-emitting diodes (OLEDs). In this work, three donor-acceptor-donor (D-A-D) typed host materials with identical non-rigid diphenylsulfone center but differing in rotation degree of peripheral amino substituted derivatives from rotating freely diphenylamine ( SODP ) to rotating partially iminodibenzyl ( SOId ) and rotating restricted carbazole ( SOCz ) were designed and synthesized. It was demonstrated that the triplet energy ( E T ) level of the materials promoted accompany with limiting the rotation degree of the peripheral groups, which was 2.72 eV for SODP , 2.73 eV for SOId and 2.78 eV for SOCz , respectively. Besides, the results of the single-carrier devices indicate SOCz possess better bipolar characteristic. Using FIrpic as guest emitter, the blue OLED with SOCz as host material exhibited superior device performance with a low turn-on voltage of 3.3 V, a maximum current efficiency ( CE ) of 30.1 cd A -1 , a maximum power efficiency ( PE ) of 32.2 lm W -1 , and a maximum external quantum efficiency ( EQE ) of 14.0%. This work provides a beneficial guideline for realizing promising host materials in efficient blue OLEDs.