In　order　to　solve　the　problem　of　low　gray　level　due　to　the　few　driving　chips　developed　based　on　the　photoelectric　characteristics　of　electrowetting　display,　a　driving　method　based　on　modulation　is　proposed　to　double　the　gray　level　of　electrowetting　display.　In　this　method,　the　driving　waveform　based　on　pulse　amplitude　modulation　and　pulse　width　modulation　hybrid　modulation　is　designed,　and　the　gray　level-luminance　curve　of　the　electrowetting　display　is　measured　and　analyzed.　On　this　basis,　the　luminance　nonlinear　correction　is　carried　out,　and　the　improvement　of　64　Gy　levels　to　127　Gy　levels　is　realized　by　the　principle　of　human　visual　persistence　phenomenon.　The　experimental　results　show　that　the　proposed　driving　scheme　can　break　through　the　limitation　of　the　driving　chip　and　realize　the　multiplication　of　gray　levels,　in　which　96%　gray　levels　increase　steadily　with　an　average　luminance　difference　of　0.07,　and　at　the　same　time　enhance　the　contrast　and　improve　the　display　effect.