The invention discloses an early-age concrete expansion coefficient measurement method, comprising the following steps: maintaining the concrete sample, sealing the concrete sample, mounting the sample, collecting the data and processing the data. The data processing method comprises the following steps: changing the temperature of the sealed concrete sample in range of -2-3 DEG C. and collectingthe data. The linear temperature-stress relation is obtained in the temperature range wherein the temperature rise is approximately coincident with the temperature decline, namely the hydration reaction of the gelling material is suppressed during measurement process, and the self-shrinkage is eliminated; and the sample is at sealing state during measurement process without water entrance and dissipation and the dry-shrinkage is also eliminated. The measured sample deformation is simple temperature deformation, thus the real concrete expansion coefficient is obtained.