As a key stage in wet spinning, compacting process served as a connection between spin and post treatment, it has significant influence on the performances of polyacrylonitrile (PAN) fiber. In this paper, the influences of temperature, time and tension on the compacting process and performance of fibers were studied. The test shows that the suitable compacting process condition is 110°C for 90s with a higher shrinkage ratio. With increasing shrinkage ratio, density and breaking elongation raise, but orientation and breaking strength decrease. To obtain better effect of compacting process, loss of orientation and breaking strength can hardly be avoided; it can be compensated by secondary draw in post process.