The specified two type of rolled and rolled+drawn near β-Ti based alloy Ti-55531 bars respectively were subjected to solution at 760 ^oC for 1 h and air-cooled, followed by aging at 560 ^oC for 4 h then air-cooling. Then their microstructure, texture characteristics, and fracture toughness were systematically investigated, in terms of the influence of different thermomechanical processing routes on the crack propagation path. The results show that thermomechanical deformation can significantly refine the primary α-phase, leading to a refined and more homogeneous microstructure of the alloy bars. The bars subjected to drawing deformation exhibit pronounced fiber textures: β-phase <110>//AD and α phase <0001>//AD. Compared with the ϕ61 mm rolled bar, the ϕ12 mm bars exhibit improved plasticity and toughness while maintaining comparable strength. The ϕ12 mm bar prepared by rolling+drawing demonstrates the best strength-toughness balance, with a fracture toughness of 34.63 MPa·m^1/2, which is 43.5% and 19.7% higher than those of the ϕ61 mm and ϕ12 mm merely rolled bars, respectively. Furthermore, crack propagation analysis indicates that the existed strong texture in the rolled+drawn bars is conductive to triggering the crack deflection effect significantly, thereby achieving geometric toughening.