Hygrothermal environment could have important effects on mechanical properties of CFRP laminates. The moisture absorption behavior of T700/3228 composite laminate was researched through moisture absorption tests, the compression performance degradation of ［0］16 and ［90］16 laminates under different hygrothermal conditions was analyzed, and the compression performance degradation mechanism was described in detail by microstructure characterization. The results show that, with the increasing of temperature and moisture, the compression strength of ［90］16 laminates decrease because of the superposition of compression expansion of resin matrix and hygrothermal expansion. The compression strength of ［0］16 laminates decreases because of the buckling deformation of resin matrix and fiber under compression loads.