The invention discloses an
electromagnetic induction full heating type steel-plastic composite pipeline connecting structure. The connecting structure comprises a wave-shaped lining ring, a pure plastic
pipe fitting, and a steel-plastic composite
pipe material with an inner plastic
pipe layer, wherein the pure plastic
pipe fitting is provided with an outer ring part, an annular bearing and inserting cavity, an inner ring
body segment and an inner ring expanding segment; the steel-plastic composite pipe material is inserted into the annular bearing and inserting cavity; a transition step is formed by the inner ring
body segment and the inner ring expanding segment; an
electromagnetic induction coil wrapped at the outer ring part is used for the
fusion welding of the steel-plastic composite pipe material and the pure plastic
pipe fitting; the free end of the lining ring leaned against the inner wall of an inner ring part is positioned outside the end part of the inner ring expanding segment; a gap exists between the free end of the lining ring and the inner wall of the adjacent inner plastic
pipe layer; fused plastic accumulated in a fused material placing space carries out the
fusion welding for the end part of the inner ring expanding segment and the inner wall of the steel-plastic composite pipe material together in a sealing manner after being condensated; and the sum of the wall thickness of the inner ring expanding segment and the wall thickness of the inner plastic
pipe layer is from 3mm to 20mm. According to the invention, reliable and gapless
fusion welding in a tight sealing manner can be formed between the steel-plastic composite pipe material and the inner ring part, so that the seepage phenomenon between the steel-plastic composite pipe material and the inner ring part is avoided.