The　Mg2Si　thermoelectric　thin　films　were　fabricated　by　radio　frequency　magnetron　sputtering　with　the　Mg-Si　binary　composite　target.　The　effects　of　sputtering　power,　vacuum　annealing　temperature　and　annealing　time　on　the　qualities　of　Mg2Si　thin　films　were　studied　to　find　out　the　optimal　preparation　process.　The　properties　of　the　thin　films　were　tested　by　scanning　electron　microscope　(SEM),　X-ray　diffraction　(XRD),　Hall　effect　tester,　film　Seebeck　coefficient　measurement　system.　As　showed　in　energy　dispersive　X-ray　spectrum　of　the　Mg2Si　thin　film　profile,　Mg　and　Si　in　the　thin　films　distribute　uniformly　and　the　mole　ratio　of　Mg　to　Si　in　thin　films　is　about　2:1,　which　is　consistent　with　the　mole　ratio　of　Mg2Si　phase.　XRD　results　show　that　the　sputtering　power,　vacuum　annealing　temperature　and　annealing　time　have　effects　on　the　film　quality.　The　test　results　of　Hall　measurement　and　Seebeck　coefficients　measurement　reveal　that　all　the　samples　are　n-type.　The　Seebeck　coefficients　are　in　the　range　of　-278.648--483.562　μV/K,　and　the　electrical　conductivities　are　in　the　range　of　1.240-46.926　S/cm.　Among　all,　the　Mg2Si　thin　film　deposited　with　120　W　and　annealed　at　400　for　3　h　have　the　highest　power　factor　of　0.364　mW/(m·K2).　©　2016,　Science　Press.　All　right　reserved.