An optical conversion device for being disposed between a reflector and a lens of an automobile headlight, comprising: a housing comprising a main body portion and the side of the main body portion designed to be placed near an open end of an headlight reflector comprising a first cavity and a second cavity located on one side of the first cavity; a rotating mechanism coupled to the housing, the rotating mechanism being rotatable relative to housing, wherein the rotating mechanism comprises a connecting shaft and a connecting member that is fixedly fitted to the connecting shaft, and the connecting shaft is coupled to the housing and is rotatable relative to the housing, and wherein the connecting member comprises a first connecting member and a second connecting member, and wherein the first connecting member and the second connecting member are respectively fixedly sleeved to both ends of the connecting shaft, the top of the first connecting member and the top of the second connecting member being respectively formed with a fixing portion, and the fixing portion being formed with a connecting structure; a driving mechanism mounted to the main body portion for driving the rotating mechanism to rotate relative to the housing, the driving mechanism comprising a motor and a gear mechanism, the motor being mounted into the first cavity, and the gear mechanism being located within the second cavity; a light blocking member which is mounted to the first connecting member and the second connecting member of the rotating mechanism, and rotatable relative to the housing along with the rotating mechanism, the light blocking member comprising a main body mounted to the first connecting member and the second connecting member, and an arc-shaped light blocking structure formed on the top of the main body for effecting light blocking switching; the main body has two holes which are respectively riveted to the connecting structure of the first connecting member and the second connecting member, and the arc-shaped light blocking structure has a concave reflecting portion; wherein the light blocking member, including its main body having holes and its arc-shaped light blocking structure having a concave reflecting portion, is a one-piece unit made of plastic, and a surface of the light blocking member is provided with a thermal barrier coating; and wherein the thermal barrier coating comprises a first metal coating disposed on a surface of the light blocking member, and a second metal coating disposed on the first metal coating. a housing comprising a main body portion and the side of the main body portion designed to be placed near an open end of an headlight reflector comprising a first cavity and a second cavity located on one side of the first cavity; a rotating mechanism coupled to the housing, the rotating mechanism being rotatable relative to housing, wherein the rotating mechanism comprises a connecting shaft and a connecting member that is fixedly fitted to the connecting shaft, and the connecting shaft is coupled to the housing and is rotatable relative to the housing, and wherein the connecting member comprises a first connecting member and a second connecting member, and wherein the first connecting member and the second connecting member are respectively fixedly sleeved to both ends of the connecting shaft, the top of the first connecting member and the top of the second connecting member being respectively formed with a fixing portion, and the fixing portion being formed with a connecting structure; a driving mechanism mounted to the main body portion for driving the rotating mechanism to rotate relative to the housing, the driving mechanism comprising a motor and a gear mechanism, the motor being mounted into the first cavity, and the gear mechanism being located within the second cavity; a light blocking member which is mounted to the first connecting member and the second connecting member of the rotating mechanism, and rotatable relative to the housing along with the rotating mechanism, the light blocking member comprising a main body mounted to the first connecting member and the second connecting member, and an arc-shaped light blocking structure formed on the top of the main body for effecting light blocking switching; the main body has two holes which are respectively riveted to the connecting structure of the first connecting member and the second connecting member, and the arc-shaped light blocking structure has a concave reflecting portion; wherein the light blocking member, including its main body having holes and its arc-shaped light blocking structure having a concave reflecting portion, is a one-piece unit made of plastic, and a surface of the light blocking member is provided with a thermal barrier coating; and wherein the thermal barrier coating comprises a first metal coating disposed on a surface of the light blocking member, and a second metal coating disposed on the first metal coating.