Fluid pipeline adapter

The utility model relates to a fluid pipeline conversion connector which comprises a first connecting pipe, a pipeline conversion assembly and a second connecting pipe. By arranging the pipeline rotating assembly capable of rotating, switching and adjusting, the inner conversion body in the main pipe body can be driven to rotate by rotating the rotating rod, so that other fluid channels on the inner conversion body are changed to be communicated with the input end and the output end of the main pipe body, and simple and convenient switching of different pipe diameter conversion is achieved; by arranging an adjusting fixing piece and a rotatable knob, a threaded rod piece is driven to rotate and is in threaded fit with the interior of the fixing piece, so that a buckling piece is pushed downwards to be in buckling fit with a rotating rotary rod, and fixing and limiting of the rotating rotary rod are achieved; the advantage of keeping the fixing stability of the internal conversion body is achieved. 本实用新型涉及一种流体