Construction control method for extension socket type rigid joint underground diaphragm wall steel box and reinforcement cage

The invention discloses a construction control method for an extension socket type rigid joint diaphragm wall steel box and a reinforcement cage. The construction control method comprises the following steps that a first-stage steel box is machined and stored; forming a groove in the first-stage groove section; hoisting and lowering the steel box section N1; adjusting the posture of the steel box segment N1; the steel box segment N2 is hoisted to a notch; the steel box sections N1 and N2 are aligned; the steel box sections N1 and N2 are in butt joint; the steel boxes after butt joint are put down; adjusting the posture of the steel box; first-stage groove section concrete pouring; processing and storing a second-stage reinforcement cage; forming a groove in a second-stage groove section; hoisting and lowering the reinforcement cage segment R1; the reinforcement cage segment R2 is hoisted to a notch; the reinforcement cage sections R1 and R2 are in butt joint; lowering the butted reinforcement cage; and second