The room temperature deformation behavior of hydrogenated TC4 alloys was studied through compression tests. The hydrogen treatment on the microstructure and deformation mechanism of the TC4 alloy at room temperature was studied by OM, TEM and XRD. Results show that hydrogen, as β stabilized element, modified the metastable phase composition of as-quenched alloys, promoted the generation of orthorhombic martensite α″ and body-centered β phase. When the H content was 0.45% (mass fraction, similarly hereinafter), the alloy mainly consisted of α″ phase, and the deformation behavior was twinning, which improved the deformation limit in a small range; while when the H content was higher than 0.59%, there were much β phase, and the deformation behavior was slipping, which improved the deformation limit greatly.