  We study thermodynamic of a dyonic AdS black hole surrounded by quintessence
dark energy where negative cosmological constant of AdS space behaves as
pressure of the black hole. We choose grand canonical ensemble of the black
hole where its magnetic charge $Q_M$ and electric potential $\Phi_E$ are hold
as constant. Our goal in this work is study physical effects of the magnetic
charge and electric potential on the thermodynamic phase transition of the
black hole in presence of quintessence dark energy. When barotropic index of
the quintessence is $\omega=-\frac{7}{9}$ we obtained that compressibility
factor of the black hole reduces to $Z_c=\frac{3}{8}$ which corresponds to the
Van der Waals fluid. We obtained analogy between the small/large black hole
phase transition and liquid/gas phase transition of the Van der Waals fluid.
Numerical calculations predict that the black hole may born $plasma$ phase
which is fourth different state of the matter which does not appear in the Van
der Waals fluid.
