The invention provides mycobacterium tuberculosis protein Rv2693c and/or Rv1984c in development and/or designing of products capable of discrimination, diagnosis, auxiliary diagnosis, screening and/or auxiliary screening of latent tuberculosis infection. The invention further provides protein chips prepared from the two mycobacterium tuberculosis proteins. The protein chips prepared in the invention are used for detecting the levels of IgM antibodies respectively corresponding to the twp proteins in serum of a patient with latent tuberculosis infection and of a normal person, and detection results of the antibodies respectively corresponding to the three protein are analyzed together so as to determine whether an examined person suffers from latent tuberculosis infection; detection results show that optimal operating points of the protein chips provided by the invention in auxiliary diagnosis of latent tuberculosis infection have specificity of 80.3% and sensitivity of 75.6%, both higher than indexes of diagnosis of latent tuberculosis infection in the prior art.