The　triboelectric　nanogenerator　(TENG)　based　on　the　coupling　effect　of　contact　electrification　and　electrostatic　induction,　with　the　advantages　of　low　cost,　flexibility,　and　high　energy　conversion　efficiency,　is　an　emerging　energy　conversion　device　with　prospects　for　broad　applications　in　micro/nano　energy,　wearable　devices,　and　self-powered　sensors.　The　results　from　theoretical　simulation　studies　of　TENGs　will　not　only　lead　to　an　understanding　of　the　working　mechanism　underlying　an　optimized　device　but　are　also　expected　to　guide　practical　applications.　This　article　summarizes　the　research　progress　in　theoretical　simulations　of　TENGs,　including　the　charge　transfer　mechanism,　the　optimization　of　device　performance,　the　equivalent　circuit　of　the　device,　and　the　power　management　circuit.　That　progress　has　also　provided　valuable　insights　into　ways　to　improve　the　energy　conversion　efficiency　and　the　power　generation　capability.　We　hope　that　this　paper　will　be　helpful　to　those　engaged　in　research　of　TENG-related　fields.