The invention discloses a transverse and longitudinal profiling device for a planting mechanism and a control method, the transverse and longitudinal profiling device comprises a frame, signal acquisition units, a signal feedback control system, a hydraulic execution system, a planting frame lifting mechanism, a planting frame and hydraulic profiling mechanisms; the signal acquisition units at the left side and the right side of the planting frame are connected by the signal feedback control system and the hydraulic execution system, the signal acquisition units sense changes of the distance between the signal acquisition units at the left side and the right side, the signal feedback control system controls the hydraulic execution system to drive the hydraulic profiling mechanisms at the left side and the right side to lift up and down respectively so as to drive the planting frame to lift up and down or rotate left and right to ensure consistent relative height of a duck mouth planting component and a ridge side, and planting depth profiling of the planting component can be realized. A distance sensor is used to sense terrain changes, and the distance sensor is sensitive to respond and has no delaying advancing phenomenon. The transverse and longitudinal profiling device has the advantages of small load, small bending moment, uniform force and simple structure, can ensure uniform planting depth, improves planting quality, and realizes the requirement of transplanting in a dry land.