Based　on　the　cantilever　beam,　this　paper　proposes　and　designs　a　novel　electret-based　electrostatic　energy　harvester　(e-EEH)　with　dual　modules:　module　I　is　a　capacitor　of　nonparallel　plate　electrodes;　module　II　is　a　multi-electrode　array　capacitor.　Two　stoppers　are　presented　in　concern　with　reliability　by　limiting　the　motion　of　proof　mass　to　prevent　capacitor　breakdown　and　pull-in.　Meanwhile　the　stoppers　serve　as　a　functional　element　to　realize　broadband　harvesting.　Considering　the　bending　of　the　cantilever　beam,　the　expression　of　the　module　Ⅰ　capacitance　is　analytically　derived　as　a　function　of　the　deflection.　Conformal　transformation　is　applied　to　obtain　the　expression　of　the　module　Ⅱ　capacitance,　simultaneously　considering　the　change　of　distance　and　overlap　area　between　movable　and　fixed　electrodes.　According　to　Hamilton＇s　principle　and　Kirchhoff＇s　circuit　law,　the　electromechanical　coupling　nonlinear　dynamics　equations　of　the　proposed　energy　harvesters　are　established.　The　output　performance　of　the　energy　harvester　is　obtained　and　analyzed　by　numerical　calculation.　The　results　show　that　the　double-model　electrostatic　energy　harvester　can　output　high　power　in　low-　frequency　broadband.　©　2022