  In this paper, we consider the phase transition of black hole in power
Maxwell invariant by means of Maxwell's equal area law. First, we review and
study the analogy of nonlinear charged black hole solutions with the Van der
Waals gas-liquid system in the extended phase space, and obtain isothermal
$P$-$v$ diagram. Then, using the Maxwell's equal area law we study the phase
transition of AdS black hole with different temperatures. Finally, we extend
the method to the black hole in the canonical (grand canonical) ensemble in
which charge (potential) is fixed at infinity. Interestingly, we find the phase
transition occurs in the both ensembles. We also study the effect of the
parameters of the black hole on the two-phase coexistence. The results show
that the black hole may go through a small-large phase transition similar to
those of usual non-gravity thermodynamic systems.
