Red blood cells aggregate from individual cells into larger aggregates during blood coagulation. This process causes the light-scattering particles to enlarge and their motion to become restricted. The size and motion of these light-scattering particles during coagulation provide valuable information on the progress of blood coagulation. This paper proposes an optical coherence tomography speckle deviation (OCT-SD) method for the noncontact assessment of blood coagulation dynamics by detecting changes in the size and motion of scattering particles. The coagulation characteristics of static and flowing blood were quantitatively evaluated through coagulation reaction time and clot formation duration by monitoring the blood coagulation process. The OCT imaging, incorporating SD analysis, enables noncontact coagulation assessment. Experimental results demonstrate that the proposed method can efficiently and accurately assess coagulation dynamics, offering significant potential for in situ coagulation detection.