GB/T 2013-2010 standard specifies three methods to determine the density of liquid Petrochemicals products: Density Meter method, U-shaped vibrating tube method and Specific Gravity bottle method. Density measurement is of great significance for qualitative analysis and volume mass conversion of Petrochemicals products. Among them, the Density Meter method is suitable for easy-to-flow transparent liquids and some viscous liquids, and the density of high-temperature liquids can be measured in a thermostatic bath; the U-shaped vibrating tube method is suitable for single-phase liquids, which requires the sample to remain in a single-phase state during processing; the Specific Gravity bottle method is suitable for most liquids, especially for accurate measurement of small amounts of samples, but not for initial distillation point liquids below 40 ° C. The choice of these methods depends on the accuracy requirements, product characteristics and experimental conditions to ensure the accuracy and comparability of measurement results.