The utility model discloses an elbow and a pipeline connecting structure, the corner of the elbow is 20 degrees, the turning radius of the center line of the elbow is 105 centimeters, the length of the elbow is 40 centimeters, and the diameter of the elbow is 16 centimeters; a pipe opening in one end of the elbow is enlarged, and the diameter of the other end is 16 cm. The pipeline connecting structure comprises a front section of pipeline, a plurality of elbows, a middle section of straight pipeline, a plurality of elbows and a rear section of pipeline which are connected in sequence. According to the elbow and the pipeline connecting structure provided by the embodiment of the utility model, the corner of the elbow is 20 degrees, the elbow can enable a plastic-coated steel pipe to conveniently avoid underground complex obstacles such as water supply, water drainage, sewage discharge and communication pipelines in the embedding process, and damage to a cable caused by a traditional turning mode is also avoided.