A needling mechanism of a single-spindle single-needle-area needling machine comprises a frame, a transmission shaft component, a needling part, first balancing mechanisms and second balancing mechanisms. The transmission shaft component comprises at least one crankshaft set. Each crankshaft set comprises a left connection shaft, a first balancing crankshaft, a needling driving crankshaft, a second balancing crankshaft and a right connection shaft. Projections, on a projective plane vertical to an axis of each left connection shaft, of the axis of the corresponding left connection shaft, a boss center line of the corresponding first balancing crankshaft, a boss center line of the corresponding second balancing crankshaft and a boss center line of the corresponding needling driving crankshaft locate at the center and three tops of an equilateral triangle. First rocker arms of the first balancing mechanisms are connected onto bosses of the first balancing crankshafts in a sleeved manner. Second rocker arms of the second balancing mechanisms are connected onto bosses of the second balancing crankshafts in a sleeved manner. Third rocker arms of lifting driving mechanisms are connected onto bosses of the needling driving crankshafts in a sleeved manner. The needling mechanism of the single-spindle single-needle-area needling machine has the advantages that stable running of the transmission shaft component can be kept during high-frequency needling, and vibration and shaking of the needling machine are reduced greatly.