In order to study the surface structure and the characteristic of the honeycomb micropore fiber，several groups of the fiber cleaned with sodium hydroxide lye with various concentration were selected as the observation samples. The surface and cross section of the fiber were observed with scan electron microscope. SEM photos with different magnifications were obtained. The results showed that the best cleaning concentration for the honeycomb micropore fiber is 1.5%NaOH .Observation and analysis of the fiber surface through SEM photos showed that there existed many linear concaves on the surface of most fibers observed. Meanwhile, elliptical concaves were also seen on the surface of some fibers. The geometric dimensions of the concaves were measured with graph processing software, and the distributions of the concave size were obtained with the statistical software. Characteristic parameters of the concaves on the surface of the fibers were put forwarded.