The experimental realization of self-bound liquids with ultracold atoms opens up new perspective to explore the liquid-gas transition in the quantum degenerate regime. In this talk, I will discuss the criticality of the liquid-gas transition in a binary Bose mixture at zero temperature. I show that, beyond a narrow stability window of the self-bound liquid, two types of liquid-gas coexistence generally exist, which transits into a homogeneous mixture upon tuning the species densities. The liquid-gas coexistence lines terminate at two distinct critical points, which are characterized by rich critical behaviors in their vicinity, including divergent susceptibility, unique phonon-mode softening, and significantly increased correlation lengths. Given the recent progress in trapping and probing cold atoms, both the transition and quantum criticality reported here can be readily investigated in a box potential.