The invention discloses a sand dredger filling construction method of a soft soil foundation embankment. The sand dredger filling construction method comprises the steps of: (1) cleaning the surface of an embankment dredger filling field; (2) measuring and lofting, and setting an elevation mark of the dredger filling construction in a dredger filling region; (3) performing the dredger filling work in a manner of segmenting and layering, to be specific, forming a cofferdam, establishing plastic water discharge plates, building construction roads, distributing grit blasting pipe lines, dredger-filling the embankment, constructing a drain opening, and constructing water collecting wells; and (4) performing stability observation and settlement observation on the dredge-filled sand land of the embankment. The sand dredger filling construction method disclosed by the invention has the advantages of solving the flatness problem of road area at coastal tidelands, rivers, fishponds and the like, performing roadbed filling of municipal administration by fully making use of the characteristics of abundant fin sand resource in the local area, reducing exploitation usage amount of the land resource, decreasing construction cost while guaranteeing construction quality of the roadbed, being simple, convenient, feasible, efficient and practical, increasing working efficiency, saving cost and creating conditions for advanced construction of the next procedure.