Data encryption method with repetitive data deleting function and system thereof

The invention relates to a data encryption method with a repetitive data deleting function and a system thereof. The data encryption method comprises the steps as follows: a repetitive data deleting program is run by a client side to generate segmentation data blocks; each client side is provided with a first key respectively; the first key is used to encrypt the segmentation data blocks and generate corresponding ciphertext data; the ciphertext data is transmitted to a service side; the corresponding first key is looked-up from an encryption look-up list by the service side; the ciphertext data is reduced into segmentation data blocks through the first key; the reduced segmentation data blocks are developed into storage data by the client side through a second key; the storage data is reduced into the segmentation data blocks by the service side through the second key, and the segmentation data blocks are encrypted into ciphertext data by the service side through the corresponding first key; and the ciphertext data is transmitted to the corresponding client side by the service side.