  The initial entanglement shared between inertial and accelerated observers
degrades due to the influence of the Unruh effect. Here, we show that the Unruh
effect can be completely eliminated by the technique of partial measurement.
The lost entanglement could be entirely retrieved or even amplified, which is
dependent on whether the optimal strength of reversed measurement is
\emph{state-independent} or \emph{state-dependent}. Our work provides a novel
and unexpected method to recover the lost entanglement under Unruh decoherence
and exhibits the ability of partial measurement as an important technique in
relativistic quantum information.
