Hypervelocity stars ( HVSs) are unbound stars escaping the gravitational potential of the Galaxy. HVSs can not only probe the extreme dynamics and physical processes at the Galactic center but also can be used as dynamical traces of integral properties of the Galaxy. Before Gaia data release 2 (DR2) was released, most of the confirmed HVSs were massive early-type O- and B-type stars in the Galactic halo. But HVS is not restricted to early-type stars but can also be observed among evolved low-mass stars, such as hot subdwarf stars and white dwarfs. Gaia DR2 release has already been used to search for new HVSs that can be unbound from the Galaxy. We are looking forward to new progress about HVSs after Gaia DR3 released.