Embankment side ditch excavation device and embankment side ditch excavation method

The invention provides an embankment side ditch excavation device and an embankment side ditch excavation method. The embankment side ditch excavating device comprises an elevation limiting steel plate, ear plates are welded on the upper surface of the elevation limiting steel plate, a shaping bucket box with an opening in one side is welded on the lower surface of the elevation limiting steel plate, the opening direction of the shaping bucket box is parallel to the width direction of the elevation limiting steel plate, and the width of the elevation limiting steel plate is larger than the width of the shaping bucket box. According to the embankment side ditch excavating device, during use, an excavating device is hoisted on a large arm of an excavator through the ear plates, the depth ofan excavated ditch is limited through the elevation limiting steel plate, so that the excavation depth of each time is kept consistent, the excavated ditch is formed once, the side ditches which are excavated and formed do no