Abstract: For the common problem of side-wall incomplete fusion in narrow groove welding of oil and gas pipelines, welding process and properties of X65 pipeline steel by narrow groove rotating arc welding were studied. Rotating arc experimental system of X65 pipeline steel plate was built, high-speed camera synchronous acquisition system was used to study behavior of rotating arc droplet, and influence of rotating arc frequencies on droplet transfer was analyzed. Through macroscopic metallographic observation of weld section morphology, influence of rotation frequency of narrow groove rotating arc GMAW on formation of weld was investigated. The results showed that high-frequency rotating arc accelerated transfer frequency of droplet, reduced size of droplet, and promoted transfer process of droplet. When rotation frequency was in the range of 5~30 Hz, good formation of weld could be obtained. Under the action of high-frequency stirring of rotating arc, surface texture of the obtained weld was very dense, and welded joints had good tensile and bending properties.