Magnetic helical soft robot has advantages of contactless and real time manipulation, as well as deep penetration depth even in the presence of obstacles. In comparison with cylindrical structures, helical soft robots have chirality (e.g., left-handedness and right-handedness) and reduced rolling resistance due to the lower mass at identical radius of curvature. However, rolling direction is determined by chirality and helix angle, resulting in deviation from linearly moving magnet. To achieve linear magnetic maneuver, previous study has varied the conditions of external magnetic field. In this study, we modified the geometry of helical coil including diameter, length, and helical pitch under the same magnetic conditions toward linear translational motion. Finally, we investigated the rolling motility of the helical soft robots on a gastric model which has complex wrinkles.