This text introduces the development trends of domestic and international research current stiuation of the thermosoope and technology at first,and established the subject of research and its programmes.Secondly that the subject of design and functional requirements of the choice of components,Thant is,first of all on the thermonmeter design fearures and design principles were introduce.Quick identified several significant temperature measuring instument is MCS-51 SCM system and temperature detection devices-based on the thermocouple,including the signal gather and amplifies;A/D converter and display some.then described in detail the principles of design,including utlizing the electric thermocouple to gather the temperature signal and amplify, and then seng into A/D converter.After entering SCM, through the display of the realization temperature of programming of software and various functions.Design the content to include the temperature transducer to design、SCM interface circuit design and software design.This text has recommended the hardware circuit part is designed in detail. Drawing a schematic,and gives the software flow chat.