A communication device and method for erasing data include setting erasing parameters and initializing the erasing parameters, erasing data in a target data block of the flash memory once, and calculate a current erasing count of the erased block, setting a first bit of the erased block as “0”. The communication device and method further determines whether other bits except the first bit of the erased block are all “1”, determines whether the current erasing count is less than the max erasing time if any bit except the first bit of the erased block is not “1”, and prompts an output if the current erasing count equals to the max erasing time.