The invention discloses a cleaning method and system for massive data, relates to the technical field of data processing, and aims to increase data cleaning speed and efficiency. The cleaning method includes: setting the number of mapping functions in a mapping reduction parallel computation framework to be N according to the number N of preset data blocks, and setting the number of a reduction function to be 1; using the N mapping functions in the mapping reduction parallel computation framework to divide the massive data into N data blocks, and cleaning data in each data block to obtain multiple cleaned data blocks; using the reduction function to integrate the multiple cleaned data blocks to obtain integrated data; cleaning the integrated data to complete the data cleaning. The cleaning system for the massive data adopts the cleaning method for cleaning the massive data.