To study the power generation characteristics of elastomer under uniaxial tensile situation, the mathematical model of dielectric elastomers under uniaxial tensile was established based on Neo-Hooken model, and the corresponding simulation model was set up in Matlab/Simulink environment. The relationships among applied force, stretch rate, initial voltage, and power generation were studied by using the simulation model; the results were compared to the experimental results, and a good agreement was found. Both simulation and experiment results showed that the generating capacity of dielectric elastomer in the power generation process was increased as the applied force, stretch rate, and initial voltage increased. Simulation results were compared with test results, and the main reason was analyzed that the experimental results were lower than the simulation ones: internal resistance of DEG, systemic obstruction, voltage loss of electronic components, measurement error and so on. The experimental results and research conclusions provide a way for later period job of DEG generator, and this study provides the basis for a further study of the power generation by dielectric elastomers, which has good practical value.