The invention discloses a portable pit digger suitable for sand land. The portable pit digger comprises a rack, the rack is provided with a feeding mechanism, a spiral digging knife, an outer cover, asoil opener, a positioning mechanism and idler wheels; the feeding mechanism is mounted on the upper part of the rack, the lower part of the feeding mechanism is connected with the spiral digging knife, the outer cover is mounted on the periphery of the spiral digging knife in a sleeving mode, the upper part of the soil opener is connected with the lower part of the spiral digging knife, and thepositioning mechanism is arranged on the side face of the rack and extends to the bottom of the rack; and the soil opener comprises a center rod, a plurality of soil opening blades are hinged in the circumferential direction of the center rod, a sensor is mounted at the front ends of the soil opening blades, each soil opening blade is slidably connected with a supporting rod, the ends, away from the soil opening blades, of the supporting rods are jointly connected with an adjusting sleeve, and the adjusting sleeve and the center rod are detachably connected. The portable pit digger can replacemanpower for pit digging, the bottom face of the sand land is dug quickly and efficiently, the labor intensity is reduced, and the good effect is achieved.