The invention discloses a pipeline detection method and device through exciting axial guided 
waves by utilizing annular 
laser. The pipeline detection method comprises the steps of: converting a round 
laser beam into an annular 
laser beam; adjusting the size of the 
radius of the annular laser beam to enable the 
radius to be in consistence with the 
radius of the annular end face of a pipeline; when the annular laser is projected on the annular end face of the pipeline, exciting guided 
waves in an axial symmetrical mode by generated 
impact load; and receiving echo signals which are generated when the guided 
waves meet with a defect by a 
signal reception device so that detection for a pipeline defect is realized. The pipeline detection method and device through exciting axial guided waves by utilizing the annular laser is good for exciting guided waves in the axial symmetrical mode of the pipeline; as a conical lens group is utilized to collect round 
flare energy on the annular end face of the pipeline, the effect of the applied 
impact load is enhanced and SNR (
Signal to 
Noise Ratio) is increased; and as the size of the radius of the annular laser beam is controlled through adjustment of a relative position between the lens group and the end face of the pipeline to adapt to the detection of pipelines with different radiuses, the pipeline detection method and device through exciting axial guided waves by utilizing the annular laser, disclosed by the invention, has the advantages of high efficiency, wide range, relatively low cost and the like.