The invention relates to a data processing method and a system, a computer device and a computer storage medium in a repetitive data deletion process. The method comprises the following steps: extracting file data of a first data amount from the backup data, detecting whether the file data conforms to a preset partitioning condition; if the file data does not conform to the partitioning condition,extracting the file data of the second data amount from the backup data, superimposing the extracted file data on the file data extracted before the extracting, and obtaining the superimposed data; if the superimposed data does not conform to the partitioning condition and the data amount of the superimposed data is smaller than the third data amount, returning the file data extracting the seconddata amount from the backup data, superimposing the extracted file data on the file data extracted before the second data amount, and obtaining the superimposed data; if the superimposed data meets apreset block partitioning condition or the data amount of the superimposed data is greater than or equal to the third data amount, the current superimposed data is determined as a re-deleted data block.