Abstract: The coefficient of thermal expansion is an essential index for evaluating the thermal stability of materials. Its accurate measurement directly affects the processing and application of materials. In this paper, the precise measurement method of the coefficient of thermal expansion was studied, the traceability of the quantity value and the influence of thermal history were explored, and the optimal experimental conditions of static force value and heating rate were selected. To establish an accurate measurement method of coefficient of thermal expansion, two kinds of certified reference materials (CRM) for the coefficient of thermal expansion, GBW (E) 130779 of aluminum and GBW (E) 130780 of polyetheretherketone (PEEK), have been developed. 6 Institutions, including research institutes, universities, and instrument manufacturers, characterized the CRMs, and the average value of the characterization results was the certified value of the CRMs. The certified values of aluminum and PEEK coefficient of thermal expansion were 24.7×10⁻⁶ K⁻¹ and 53.9×10⁻⁶ K⁻¹, with relative extended uncertainty of 2% and 3% (k=2).