Various embodiments disclose a colorimetric absorbance measurement method and a system for performing the same. The method comprises driving a reaction tray carrying a plurality of reaction cuvettes to rotate at a speed; transferring or rotating filters on a filter wheel to a light path of a light beam, starting from a filter of a first wavelength; and sampling photoelectric data when the light beam has passed through each reaction cuvette in some embodiments. The method ensures consistency in the measurement and synchronization between the calibration and the sample test and reliability of the measurements. Various embodiments simplify data processing and reduce the complexity of the system.