本文提出了一种测试固体材料热膨胀系数的新方法,介绍了该方法的基本原理及计算公式。在此基础上设计了一套新的示差膨胀计,并建立了一台简易新示差膨胀仪。利用该仪器对纯铜材料进行了测试,其结果与已发表的文献数据比较接近。同时对该法的误差进行了分析。本文还叙述了新示差法可应用的前景和不足。 This paper presents a new method of testing the thermal expansion coefficient of solid materials, introduces the basic principles and calculation formulas of the method. Based on this, a new set of differential dilatometer was designed and a simple new differential dilatometer was established. The instrument was used to test the pure copper material, the result is close to the published literature data. At the same time, the error of the law was analyzed. This article also describes the prospects and deficiencies of the new differential method.