The utility model provides an umbrella-shaped vibrationless compaction reaming device, which includes a columnar skeleton; a hydraulic cylinder is disposed on an upper part of an inner part of the columnar skeleton; a conical head is provided on a lower part of the columnar skeleton; the conical head is connected with a piston rod of the hydraulic cylinder; soil extruding blades and soil sealing blades are provided outside the columnar skeleton; the soil sealing blades are arranged in gaps of outer sides of the soil extruding blades; one ends of the soil extruding blades and the soil sealing blades are movably connected on the upper part of the columnar skeleton; sliding rods are provided on the other ends of the soil extruding blades; and the sliding rods pass through the columnar skeleton and are in point contact with the conical head. When the device works, a hydraulic oil is driven by an external hydraulic station to be injected into the hydraulic cylinder, the piston in the hydraulic cylinder slides downwards, the conical head slides downwards along with movement of the piston, then the sliding rods are pushed out in a horizontal direction, the soil extruding blades and the soil sealing blades are synchronously unfolded under the action of the sliding rods, and then the device is pulled out for reaming at one time upon an external force and compaction on a foundation soil is carried out. The umbrella shaped vibrationless compaction reaming device is mainly applied to compaction reinforcing treatment on a foundation of a railway, a road, a house or the like in a collapse loess region and a mollisol region.