The invention discloses a rigid wall enclosure system with rectangular reinforcement cages and a construction method thereof. By means of the provided rigid wall enclosure system with the rectangular reinforcement cages and the construction method thereof, the rigidity of a water stop curtain can be effectively improved, accordingly, the capacity for resisting the active earth pressure coming from the outside of a foundation pit is improved, and deformation of the foundation pit is relieved. The rigid wall enclosure system with the rectangular reinforcement cages comprises a rigid wall formed by a plurality of concrete piles arranged in sequence, every two adjacent concrete piles are engaged with each other, and the reinforcement cages are embedded in all the concrete piles; and the part where the two adjacent concrete piles are engaged with each other is separated from the corresponding reinforcement cage, and the cross sections of the reinforcement cages are rectangular.