The invention discloses a precise positioning device capable of rotating by 360 degrees. The precise positioning device capable of rotating by 360 degrees comprises a base, a shaft sleeve, a rotary shaft, a positioning disc, a graduated disc, a locking ring and a locking screw, wherein the base is fixed to the side wall of the shaft sleeve, threaded sections are arranged at the two ends of the rotary shaft, a limiting disc is arranged on the rotary shaft, the rotary shaft penetrates through a shaft hole of the shaft sleeve from the limiting end of the limiting disc and is sleeved with a locking ring, the graduated disc and the positioning disc in sequence from outside to inside, the positioning disc is connected and fixed to the end face of the shaft sleeve, the graduated disc is fixed to the rotary shaft, the locking ring is connected with the end of the rotary shaft in a threaded mode, and a locking screw used for locking the rotary shaft is installed on the shaft sleeve. According to the precise positioning device capable of rotating by 360 degrees, a part can be positioned accurately, indexing is precise, operation is easy, using is convenient, both installation and dismantling are rapid, and clamping and dismantling can be achieved by a single person. The precise positioning device can be installed on a working table of any electric cutting device to be used and is mainly used for machining of narrow gaps and complicated shapes, such as special shapes, on a rotary body.