The research progress of microbending at home and abroad and IEC TR 62221-2001 technical report are introduced. Several microbending tests of G.652 D and G.657 A2 fibers are carried out by using method B（fixed diameter drum） in the technical report. The micro-bending attenuation and attenuation change of optical fiber were tested after rewinding

2 h at room temperature after rewinding

1 h at-60℃ and 24 h at-60℃ and the test results were analyzed in depth. The repeatability and operability of method B are obtained through microbending tests.