The invention relates to the technical field of the side ditch construction and in particular to a full-automatic digital control slip form machine roadbed side ditch construction method. The construction method comprises the following steps: through installing a full-automatic digital control slip form machine for side ditch construction, wherein the full-automatic digital control slip form machine comprises an outer side template and a concrete pouring module, in a working process, forming a cavity for pouring concrete by matching a surface of the outer side template and a ditch surface of the side ditch, through the concrete pouring module, pushing the concrete into the cavity and extruding to form a concrete layer, wherein the full-automatic digital control slip form machine further comprises a walking module, a guiding module and an automatic joint-cutting module, through the walking module and the guiding module, enabling the full-automatic digital control slip form machine to bewalked along a direction of the ditch, and joint-cutting automatically. The related construction method comprises the steps of construction preparation, side ditch excavation, side ditch cast-in-situforming, secondary plastering and checking. The new side ditch construction method is capable of combining with functions of automatic walking, automatic guiding and automatic joint-cutting, solvinga problem that a traditional side ditch construction method is complicated in process, and improving working efficiency.