For lack of methods in dental pulp vitality detection,large error and pain to the patient using current ways,a new instrument present in this paper,which based on fluorescence detection.The basic function of hardware modules and the flow of software are all described in detail,also include the design parameters.A touch screen and a TFT screen are used in the instrument,so it can display the result vividly,and can be set the parameter easily.In simple test,the nonvital teeth can be distinguished from the healthy teech.To change the fluorescent filter，the instrument can also be used in the detection of dental caries and dental plaque.