The invention relates to a preparation method of polyimide profiled fibers. The method comprises the following steps of: (1) preparing a polyamic acid solution; (2) forming by dry spinning; and (3) performing cyclization on the as-spun fibers. The dry spinning process is adopted to prepare polyimide profiled fibers, which has high production efficiency, simple procedures and strong operability, makes solvent volatilization more convenient and can achieve the effect of controlling the degree of profile of polyimide fibers. The prepared polyimide profiled fibers have good mechanical properties and high specific surface areas, maintain good dimensional stability at a high temperature, and can be widely applied to reinforcing fibers of composite materials, protective clothing against high-level radiation and other severe conditions, filtering materials used in high temperature mining conditions and so on.