Compared with α + β titanium alloys, near-β titanium alloys exhibit higher specific strength, better strength-toughness matching, superior hardenability, and greater hot and cold forming capabilities. They are widely used as main load-bearing components in advanced aviation vehicles. During the preparation of titanium alloys, the content, grain shape, and grain size of the primary α phase and secondary α phase are often controlled through thermal deformation and heat treatment, which affect the overall properties of titanium alloys. In recent years, research has revealed that the grain size and orientation within the original β phases also impact crucial properties of titanium alloys such as their strength, plasticity, and fracture toughness. This is because on the one hand, during the phase transformation of titanium alloys from β phase to α phase, the morphology, size, and orientation of the α phase are directly controlled by the β phase; on the other hand, the titanium alloy still contains residual β phase in the service state, which exerts a particularly considerable impact on near-β titanium alloys. To explore methods for preparing large β grains through the control of texture and to systematically investigate the effect of typical β phase textures on the room-temperature tensile and impact properties of titanium alloys, TC18 titanium alloy billet having {100} oriented β grain (exceeding 50 mm × 50 mm × 100 mm) was prepared using six-pass forging at α + β region, one-pass forging at quasi-β region, and high-temperature annealing. The tensile and impact toughness at 20 ^oC were measured in the <100>, <110>, and <111> directions of the large β grain, while SEM and EBSD were employed to study the microstructure and texture evolution during the preparation process. During forging at α + β region, the billet was compressed in length direction by 50% and was stretched to its original size at 30 ^oC below transformation temperature (T_β ). During forging at quasi-β region, the billet was compressed in length direction by 30% at 15 ^oC above T_β. The high temperature annealing involved holding the billet at 25 ^oC above T_β for 12 h, followed by water quenching. The results showed that the key mechanical properties of TC18 titanium alloy were considerably affected by the change in the orientation of the β phase. For the large β grains of TC18 titanium alloy, the highest values for strength, elastic modulus, and impact toughness were observed in the <111> direction and then in the <110> direction, whereas the lowest values for these properties were observed in the <100> direction. The strength, elastic modulus, and impact toughness in the <110> direction were similar to those without the β phase texture. The samples having a strong <111> β phase texture showed a 14.8% higher in tensile strength, a 12.2% higher in yield strength, a 13.6% higher in impact toughness, and only a slight decrease in plasticity than samples without an obvious β phase texture. Large {100} grains formed at the center of the billets' cross section during forging, and they gradually grew toward the surface with increasing forging times; this phenomenon was facilitated by the subgrain boundary merging of grains having a similar orientation.