In this paper, the microstructure evolution and deformation mechanism at room temperature and cryogenic temperature of cryogenic titanium alloy bars were investigated through Mo equivalent controlling. The results showed that the precipitation of α phase was affected by the Mo equivalent. With increasing of Mo equivalent, β phase stability was improved, which makes the formation of single β grain with no α phase precipitation. As for the low Mo equivalent alloy, the basktweave microstructure occurred. Compared the properties at room temperature of two alloys at room temperature, the plasticity of β alloy was lower, which is mainly caused by the difference of slip ability between α phase and β phase. The slip ability of β phase is better than α phase at room temperature, which makes the excellent plasticity deformation ability of β phase, as a result, a large amount of dimples occurred in the tensile fracture. What′s more, the strength of near β alloy was higher, which is mainly caused by the obstructive effect of interweaved α lamellar in basktweave microstructure during deformation. The higher Schmid Factor of near β alloy made the dislocation slip easier, which causes the dislocation slip acted as mainly deformation mechanism at room temperature and cryogenic temperature, and the deformation twins can also be activated at cryogenic temperature. For the β alloy, stress concentration occurred at grain boundary, because of the pile-up dislocations, and the higher V content made the higher β stability, which makes the fracture of sample at cryogenic temperature with no stress induced mechanical twins. As a result, poor ductility was obtained, and the brittle fracture characteristics was also occurred at cryogenic temperature.