Liquid identification becomes more and more important in the safety inspection at the subway, airport, and railway. Non-contact liquid security identification is the best way, because it can avoid the contamination of the liquids and the injuries caused by some corrosive and toxic liquids. The paper designed the non-contact Infra-Red thermometer based on the sensor of MLX90614 and the most favored microprocessor STM32F107 for the non-contact liquid security identification system. Completed the hardware circuit, made the PCB plate, programmed the software with Keil C and de- bugged by Keil uVision4 MDK V4.22. Then, studied the effects by measuring the temperature differences using bottles with various shapes, materials, sizes and wall thickness at different distances. The system meets the requirements of high reliability, low costs, low power consumption, real time response and the demands of the non-contact liquid security iden- tification system.