Transition　metal　dichalcogenides　(TMDCs)　are　promising　for　future　electronic　and　optoelectronic　applications,　such　as　field　effect　transistors　(FETs),　for　their　high　carrier　mobility　with　a　thin　layer,　wide　bandgap,　and　organic-like　flexibility.　However,　background　doping　and　unipolar　electrical　characteristics　are　commonly　observed　in　TMDCs　and　their　based　FETs　due　to　the　naturally　inevitable　vacancy　defects,　which　limit　their　application　in　electronics　and　optoelectronics　systems.　Here,　taking　MoS2　as　an　example,　in　a　TMDC　FET,　ambipolar　properties　were　achieved　at　room　temperature　by　introducing　an　amorphous　solid　ionic　conductor　lithium　tantalate　(LiTaO3)　as　the　gate　dielectric,　which　could　guarantee　the　modulation　of　the　Fermi　level　in　the　MoS2　channel　by　the　gate　electric　field.　Based　on　the　modulation　mechanisms　by　the　solid　ionic　conductor-gated　electric　field　for　the　transformation　of　conduction　mode,　the　three-terminal　device　exhibits　a　gate-controlled　rectifying,　that　is,　thyristor　performance　with　a　high　rectification　ratio　over　300　obtained　at　a　low　gate　voltage　of　2V.　The　present　results　show　the　great　potential　of　TMDCs　in　future　logic　and　other　electronic　device　applications.