The invention provides a phase change material, a phase change storage unit and a preparation method thereof, wherein the phase change material comprises a tantalum element, an antimony element and atellurium element, wherein the chemical formula of the phase change material is TaxSbyTez, wherein x, y and z refer to atomic percentages of elements, wherein x is greater than or equal to 1 and lessthan or equal to 25, y is greater than or equal to 0.5, z is less than or equal to 3, and x+y+z is equal to 100. The TaxSbyTez phase change film material disclosed by the invention has the characteristics of being high in phase change speed, outstanding in heat stability, high in data retention capability, long in cycle life, high in rate of finished products and the like, wherein Ta5.7Sb37.7Te56.6 has 10 years of data retention at 165 DEG C, and when being applied to a phase change storage device unit, the operation speed of 6ns and the erase number of one million or above can be achieved; meanwhile, the TaxSbyTez phase change material has very small crystal particles, and the sizes of the crystal particles is still smaller than 30 nm after annealing treatment at 400 DEG C for 30min, which is very important for stability, low power consumption and finished product rate of the device. The preparation method of the phase change memory unit is compatible with a CMOS process and is convenient for accurately controlling the components of the phase change material.