  We show that non-Hermitian biorthogonal many-body phase transitions can be
characterized by the enhanced decay of Loschmidt echo. The quantum criticality
is numerically investigated in a non-Hermitian transverse field Ising model by
performing the finite-size dynamical scaling of Loschmidt echo. We determine
the equilibrium correlation length critical exponents that are consistent with
previous results from the exact diagonalization. More importantly, we introduce
a simple method to detect quantum phase transitions with the short-time average
of rate function motivated by the critically enhanced decay behavior of
Loschmidt echo. Our studies show how to detect equilibrium many-body phase
transitions with biorthogonal Loschmidt echo that can be observed in future
experiments via quantum dynamics after a quench.
