The coefficient of thermal expansion (CTE) is an important thermal parameter for thin films, which is a critical issue in the calculation and analysis of the thermal stress and residual stress of thin films. In this paper, the CTEs of titanium nitride (TiN) and aluminum (Al) films were measured by single-substrate and dualsubstrate method based on the thermally induced bending principle, respectively. Feasibility and tolerance of the dual-substrate method were mainly investigated. The results show that difference in the elastic modulus of films is an important factor affects the calculation accuracy of CTEs tested by the dual-substrate method. When the difference of elastic modulus is small, the CTEs measured by the dual-substrate method agree well with the results by the single-substrate method. The dual-substrate method became inapplicable when there is big elasticmodulus difference of the films on different materials. In addition, the difference of CTE values between the thin film and bulk TiN and Al were also discussed according to the characterizations of the morphology, structure and residual stress of the films. The results also show that the compressive residual stress will increase the film CTE, while the tensile residual stress can decrease the film CTE.