The invention discloses an improved sleeve type inner anchor head which comprises an anchor rod, a sleeve and a cone frustum wedge. The sleeve is of a hollow structure, openings are formed in two ends of the hollow structure, the inner wall of an upper end of the sleeve is matched with the outer wall of the anchor rod, the inner wall of a lower end of the sleeve is matched with the outer wall of the upper end of the cone frustum wedge, the upper end of the sleeve is fixedly connected with the anchor rod, and a plurality of cut grooves are circumferentially formed in the lower end of the sleeve. The improved sleeve type inner anchor head has the advantages of safety, reliability, good durability and wide application range.