Dielectric elastomer is a kind of typical soft active material. It can deform obviously when subjected to an external voltage. Dielectric elastomers usually fail when electromechanical instability, snap-through instability or electrical breakdown occurs. If the failure can be avoided, there will be adiabatic temperature change and isothermal entropy change in dielectric elastomer. Here, we investigated the stability (electromechanical stability, snap-through stability), failure (electrical breakdown, loss of tension, rupture, instability), voltage induced deformation, entropy change and temperature change of dielectric elastomers. Considering the influence of temperature, we established the temperature, polarization and deformation coupling thermodynamical free energy model to calculate the electric field induced deformation, adiabatic temperature change and isothermal entropy change of dielectric elastomers. These simulation results are helpful for guidance of the design and fabrication of excellent transducer based on dielectric elastomers.