Food and transportation industries waste a large amount of cooking oil and gasoline, and illegal businesses will put these unsafe-protected waste oil back into use, endangering consumer health and aviation safety. It has significant value in the field measurement of the freezing point of oil liquid and solvent. For cooking oil, different types of oil usually have different freezing points, for example, palm oil and olive oil are 5℃, while soybean oil is -8℃, peanut oil is -10℃, rapeseed oil is -15℃, and blend oil is 2-13℃. The freezing point range of these oils is the same, and we can measure the freezing point of the oil to identify the type of oil and identify the gutter oil or regular cooking oil. In winter, in high latitudes, if the freezing point of the aircraft is less than the ambient temperature, it will cause abnormal working conditions and even accidents. And query from the Internet is currently using mechanical pump refrigeration and because of volume expansion can only desktop on the laboratory desktop application. The price is high, between twenty thousand to one hundred thousand CNY, no portable can be measured in the work site oil freezing point instrument. This project uses semiconductor refrigeration plates of small volume, no noise, low cost, low voltage, small power of the freezing point. The advantage of the invention is a kind of portable test instrument, measuring temperature range between -20 to -60 ℃, the volume within the scope of the 30 * 30 * 80 cm, weight within 10 kilograms, the reaction time in 20 minutes, within the cost and the price is in 2000 CNY of the refrigeration equipment. Keywords: portable, semiconductor, oil solidification point, refrigeration