The high-pressure phases of bromoform at zero temperature have been investigated by first-principles pseudopotential plane-wave calculations based on the density functional theory. A new high-pressure polar phase, E, with space group CC has been found after a series of simulated annealing and geometry optimizations. Our calculated enthalpies showed that the transition from beta phase to gamma phase occurs at 1 GPa, then the gamma phase transforms to the E phase at 90 GPa. In addition, the Br ... Br and C-H ... Br interactions are the key factors for the polar aggregation in the E phase. Further calculations show that the insulate-metal transition in E phase due to band overlap happens at similar to 130 GPa.