Deep and shallow foundation pit construction structure and construction method

The invention discloses a deep and shallow foundation pit construction structure. The deep and shallow foundation pit construction structure comprises a deep foundation pit and a shallow foundation pit, a support pile is arranged between the deep foundation pit and the shallow foundation pit, a crown beam is fixedly arranged at the top of the support pile and is of an annular structure surrounding the deep foundation pit, a haunched beam is arranged on the side face, located on one side of the shallow foundation pit, of the crown beam, the longitudinal section of the haunched beam is of an inverted trapezoidal structure, and the haunched beam is used for tying the crown beam. The haunched beam is additionally arranged on the outer side of the crown beam, so that the stability of the supporting pile is effectively improved, the bearing capacity of the supporting pile is greatly improved, the supporting pile can meet the construction requirement that the shallow foundation pit is excavated firstly and then the