Abstract: An ultrahigh-pressure acid-fracturing isodiametric hose assembly, comprising a hose body and a metal joint. The metal joint comprises an inner tube, a first outer tube the inner tube, and a second outer tube. The first outer tube and the second outer tube each is an independent pressing part. An external groove is provided at an outer wall of the inner tube. An end of the first outer tube comprises an internal ridge which matches the external groove for snapping. The terminal of the inner tube comprises a connecting portion. An outer wall of the inner tube comprises a first protrusion, and an inner wall of the first outer tube comprises a second protrusion engaging with the first protrusion. The hose body is clamped between the first protrusion and the second protrusion that are engaged. An inner wall of the second outer tube comprises multiple micro-protrusions.