Abstract: This paper reviewed the history of some elastic wave techniques used for the inspection of rock bolts and pointed out that to solve the problem of precise detection of the length of the anchor rod, it is impossible to rely solely on the improvement of the existing detection technology. Its breakthrough direction may require the design of new high-sensitivity sensors combined with acoustic metamaterials, and use of pseudo-random coding methods in spread-spectrum techniques. With regard to the problem of obtaining the fullness of mortar, the existing methods are too rough and the application theory needs to be improved urgently. The next work is mathematical simulation calculation and indoor physical model experimental work under rock bolt anchoring system conditions. It is possible to try to study the correlation between the frequency of reflection waves at the bottom of the rock bolt and the mortar fullness, and establish the relationship between the two. In the end, some suggestions are preoposed for the main problems in the elastic wave detection technology of the rock bolt anchoring in China.