在采用U形振动管法测定原油密度时，原油黏度会对密度测定结果产生影响，导致原油贸易结算产生偏差。笔者主要分析了U形振动管法测试原油密度的原理和标准，并对不同种类原油黏度对于密度测定结果的影响进行了研究。结果表明：在使用不带黏度修正功能的数字密度计测试时，应注意严格按标准要求提高测试温度，减少黏度的影响；在使用带黏度修正功能的数字密度计测试时，应注意按仪器厂商说明书校准仪器，使测定结果更加合理。

When measuring the density of crude oil by U-shaped vibrating tube method, the crude oil viscosity would affect the density test results, which would lead to the deviation of crude oil trade settlement. The principle and standard of U-shaped vibrating tube method measuring crude oil density were introduced, and the effects of viscosity of different types of crude oil on the density test results were studied. The results show that when using the digital density meter without viscosity correction function, it should be strictly in accordance with the requirements of the standard, improve the test temperature and reduce the effects of viscosity. When using the digital density meter with viscosity correction function, it should pay attention to instrument calibration according to the manufacturer’s specifications to make test results more reasonable.