The work aims to propose an improved simple test method for physical parameters of cold storage materials, which can serve the performance test of ice bags. The calculation formula of latent heat and specific heat of solid state was improved by considering the effect of sensible heat caused by the different temperatures at the beginning and end of phase transition. The intersection of the tangent of the inflection point of the curve and the tangent of the temperature point corresponding to the minimum point of the first derivative function of the curve was used as the end point of the phase transition. Deionized water was used as the representative of inorganic phase change cold storage material, and count Rocca cold storage was used as the representative of composite phase change cold storage material for experimental verification. The measured parameters of liquid specific heat, phase change latent heat and solid specific heat of deionized water and count Rocca cryogen were within 8.1% of the theoretical value. Compared with the original measurement method, the measurement accuracy of liquid specific heat and solid specific heat was unchanged, and the accuracy of latent heat value of phase change increased by 2%. The improved method is accurate and feasible for the determination of the physical parameters of related cold storage.