A server includes a casing, a bottom plate, a first hard disk module, a second hard disk module, and a lifting device. The bottom plate is disposed in the casing and configured to be sliding relative to the casing. The first hard disk module is movably disposed on the bottom plate. The first hard disk module includes a track. The second hard disk module is fixed on the bottom plate and disposed behind the first hard disk module. The lifting device moves up the first hard disk module when the bottom plate is pulled out of the casing, and the lifting device moves down the first hard disk module when the bottom plate is pushed into the casing. A drawer lifting device is also disclosed.