A data storage method applying to a phase change memory and the phase change memory are provided. After obtaining to-be-stored data, the phase change memory (PCM) generates an erase pulse signal and a write pulse signal according to the to-be-stored data. The to-be-stored data is multi-bit data. The write pulse signal includes at least two contiguous pulses. Intervals between the at least two contiguous pulses are the same. The intervals between the at least two contiguous pulses have a value determined according to the to-be-stored data. The PCM applies the erase pulse signal to a storage unit of the PCM to enable the storage unit to change to a crystalline state. Further, the write pulse signal is applied to the storage unit to enable the storage unit to change to an amorphous state corresponding to a first resistance value, where the amorphous state represents the to-be-stored data.