The utility model discloses a rectangular foundation trench hole-forming device capable of rapidly excavating soil, which belongs to the field of capital construction equipment and comprises a mounting bracket, a rectangular hole-forming frame, a plurality of vibration devices and an
auger soil-excavating device, the mounting bracket is mounted at the output end of an
excavator, the vibration devices are mounted at the bottom end of the mounting bracket, the rectangular hole-forming frame is mounted at the output ends of the vibration devices, and the
auger soil-excavating device is mounted on the rectangular hole-forming frame. The driving device is installed on the installation support, the top end of the
drill rod penetrates through the installation support and is fixedly connected with the output end of the driving device, the bottom end of the
drill rod penetrates through and extends out of the rectangular hole forming frame, and the
drill rod is slidably connected with the top wall of the rectangular hole forming frame; the
auger blade is fixedly wound on the side wall of the drill rod, and soil outlet holes are formed in the side wall of the rectangular hole forming frame. According to the utility model, the rectangular forming hole frame extends downwards into the soil through the vibrating device, the auger blades rotate to crush the soil synchronously and
discharge the soil in the rectangular forming hole frame from the soil outlet holes, so that the
rapid construction of the rectangular foundation trench is completed, and the working efficiency is improved.