Kinetics of solidification of liquid benzene under high pressure has attracted much attention of scientists, and it is also one of long-standing disputes. In the present work, the gas-gun technique is combined with a recently developed measurement method of light transmittance, and the time dependence of light transmittance of liquid benzene is directly observed during successive multiply shock-compressions. The analysis shows that the transmittance decrease is caused by light scattering effects in a non-uniform optical medium, which is formed by local phase transformation of liquid-solid, and that the scattering feature reflects both the time relaxation and the spacial accumulation of transition process. The argument whether the liquid-solid phase transformation happens under multi-shock compression is clarified, and important experimental evidence is provided for the study of phase transformation Kinetics.