The invention provides a data integrity testing system comprising a data processing server, for generating a matrix M according to data to be tested and storing the matrix in s ordinary servers, wherein the data processing server is also used for obtaining a matrix R according to a pseudorandom function f, a key kprf and seeds Sip, obtaining a matrix R<-> according to the matrix R and a generator g, obtaining a redundancy matrix S according to the matrix M, an s*k-order Cauchy matrix A and the matrix R, and storing the redundancy matrix S and the matrix R<-> in k redundant servers; the data processing server is also used for obtaining a matrix V according to the Cauchy matrix A and the generator g and transmitting the matrix V to a testing server; the testing server is used for testing the data to be tested and outputting test results. The method implements the testing for data integrity while protecting the privacy of information, and generates the redundancy matrix S and the matrix R<-> for data testing and restoration.