  We study a one-dimensional lattice model subject to non-Hermitian
quasiperiodic potentials. Firstly, we strictly demonstrate that there exists an
interesting dual mapping relation between $|a|<1$ and $|a|>1$ with regard to
the potential tuning parameter $a$. The localization property of $|a|<1$ can be
directly mapping to that of $|a|>1$, the analytical expression of the mobility
edge of $|a|>1$ is therefore obtained through spectral properties of $|a|<1$.
More impressive, we prove rigorously that even if the phase $\theta \neq 0$ in
quasiperiodic potentials, the model becomes non-$\mathcal{PT}$ symmetric,
however, there still exists a new type of real-complex transition driven by
non-Hermitian disorder, which is a new universality class beyond $\mathcal{PT}$
symmetric class.
