Abstract: A reagent reaction determination method and device applied to a test tube, a computer-readable storage medium and a test tube, wherein, the reagent reaction determination method comprises: outputting a brightness control signal to the light-incident component to control the light-incident component to emit the RGB light, and to adjust the brightness control signal according to a preset step length, so as to adjust the brightness of the RGB light; detecting brightness variations of the light derived by the light-emergent component to generate an electrical signal detection value; perform an interpolation calculation on the present brightness control signal to obtain an estimated value of the brightness control signal when the electrical signal detection value is less than a preset threshold, and determining a reaction result in the reagent reaction chamber according to the estimated value of the brightness control signal. The reagent reaction determination device can greatly improve the user experience.