The invention discloses a rotary sample stage device based on an atomic force microscope. The device includes a top cover, thin ring bodies, a base, a pin and a spring, wherein the base is fixed on anatomic force microscope disposing table, the thin ring bodies are fixedly connected with the base, the top cover is matched with the thin ring bodies and the base in shape, a sample is driven throughrotation of the top cover to realize free rotation, different convex teeth are sequentially dialed by the spring, accurate small-angle rotation is realized, and the auxiliary positioning function isprovided by the pin and the spring. The device is advantaged in that the device can be adaptive to the small low sample disposing space of the atomic force microscope, an extra rotation angle scale isprovided for the sample under the strict size and weight limits, the self-locking function is achieved, functions of the atomic force microscope are improved while normal operation of the atomic force microscope is not influenced, and application occasions and the research scope are expanded.