The invention relates to a quenching device for glass tempering. The quenching device for glass tempering comprises a quenching tank (1) containing cooling liquid (2), wherein an inclined liquid floating device (3) is arranged in the quenching tank (1), one side of the liquid floating device (3) is arranged on a side wall of the quenching tank (1), and the liquid floating device (3) comprises a table top (31) and a lower side wall (32); the table top (31) and a lower side wall (32) form a closed box body (33); the table top (31) is provided with a group of spray holes (31a), the lower end of each spray hole (31a) is connected with the inside of the box body (33), and the bottom of the box body (33) is connected with a first pump (5) through a liquid supply pipe (4). The quenching device for glass tempering has the advantages that the device is applicable to tempering of large-area flat-plate thin glass, generation of pinch marks or bending deformation in a quenching process, the tempering quality of glass is ensured, dissipation of quenching heat is facilitated, heat exchange efficiency is high, the thin glass with large area can be uniformly cooled, continuous production can be realized, and the energy consumption and cost are reduced.