The invention discloses an engaged pile-double wall steel combined cofferdam connecting structure and a construction operation technology. The engaged pile-double wall steel combined cofferdam connecting structure and the construction operation technology are characterized in that the novel engaged pile-double wall steel combined cofferdam connecting structure is provided with an embedded part A,an embedded part B, a ring-shaped groove formed in the contact position of the top of a crown beam and an outer wall plate of a double wall steel cofferdam, a groove interior water stop material, anchor bars stretching in the crown beam and the double wall steel cofferdam and concrete poured in a sandwich cabin of the double wall steel cofferdam. The embedded part A is directly connected with theinner wall plate of the double wall steel cofferdam. The ring-shaped groove is formed in the contact position of the top of the crown beam and the outer wall plate. The embedded part B is arranged atthe bottom of the ring-shaped groove. The outer wall plate is connected with the embedded part B at the bottom of the ring-shaped groove. A certain clearance is reserved between the outer wall plate and the position, close to the outer wall of an engaged pile, of groove wall of the ring-shaped groove, and the clearance is filled with the water stop material. The engaged pile-double wall steel combined cofferdam connecting structure and the construction operation technology are specific to engaged pile-double wall steel combined cofferdams, and safe of the combined cofferdam in the whole building and use period is ensured under the premise that construction convenience is achieved.