In this paper we report on the Ti:sapphire mode-locked femtosecond laser based optical frequency comb apparatus and developed by NIM its application in optical frequency measurement of the I2 stabilized 532nm Nd∶YAG laser installed in NIM. The measurement result of 127I2 R(56)32-10 hyperfine transition is 563260223512991±20　(Hz), with a relative frequency uncertainty of 3.6×10-14. To our knowledge，this result is the first optical frequency measurement in China which is referenced directly to the Cs microwave frequency standard.