Ditch construction mechanism

The utility model discloses a ditch construction mechanism which comprises a formwork positioning device and a formwork assembly, the formwork positioning device comprises a fixing plate, a height adjusting assembly, a horizontal adjusting assembly and a positioning piece, and the fixing plate is installed at the bottom of a ditch; the height adjusting assembly comprises a vertical adjusting rod and a first mounting seat, the vertical adjusting rod is mounted on the fixing plate, and the first mounting seat is configured to be capable of adjusting the height of the first mounting seat on the vertical adjusting rod; the horizontal adjusting assembly comprises a horizontal adjusting rod and at least two second mounting seats, and the second mounting seats are configured to be capable of adjusting the positions of the second mounting seats on the horizontal adjusting rod; the positioning piece is mounted at the bottom of the second mounting seat and is provided with a positioning cavity; the template assembly co