The invention discloses a method for reinforcing a firm soft foundation operating road. The method comprises the steps of (a) making marks on the ground which is cracked, or protruded or needs to be reinforced of the operating road which is characterized by differential settlement, poor roadbed stability or soft clay foundation every 1-3m longitudinally and horizontally; (b) drilling holes in the roadbed (1) with the marks with a flexible drill bit, wherein the diameter of each hole is approximately 100mm; (c) drilling holes in the soft foundation (2) under the roadbed with the flexible drill bit, wherein the diameter of each hole is 300-600mm, and the depth of each hole is 3-30m; (d) taking out the drill bit, placing a conduit with an outer diameter of 100mm approximately into each hole, and pouring mortar or concrete into the conduit; (e) taking out the conduit and drying the conduit under air to achieve the reinforcement. According to the method for reinforcing the firm soft foundation operating road, drilling piles are constructed in the foundation under an embankment of the operating road, the stability of the roadbed is improved by means of the drilling piles, settlement is reduced, damage to the roadbed and road surface is small, the finished piles are reliable in quality, and the soil squeezing effect is avoided.