该文简要介绍了热失重法计算砂岩孔隙度的原理,利用地化样品热解前后的质量变化,推导出砂岩孔隙度计算公式;分析了泥质、钙质胶结物对孔隙度计算值的影响,建立了相应的校正计算公式;实例证明热失重法与室内测定孔隙法的原理是相同的、数值是接近的,该方法是一种经济、快速的砂岩孔隙度测定方法。 This paper briefly introduces the principle of calculating the porosity of sandstone by TG method, and derives the calculation formula of the porosity of sandstone by using the change of mass before and after pyrolysis of geochemical samples. The influence of clay and calcareous cement on the calculated value of porosity is analyzed , And the corresponding correction formula was established. The example proves that the principle of thermal weight loss method is the same as that of indoor pore testing method, and the numerical value is close. This method is an economical and rapid method for determining the porosity of sandstone.