To solve the existing problems, such as sludge volume increasing, high consumption of chemical reagent and energy during the sludge treatment and disposal, a sludge conditioning method, called self-flocculation, was proposed. This approach enhanced the dewatering efficiency of sludge via the utilization of the self-flocculation function of the extracellular polymeric substance (EPS). By orthogonal and single factor experiments, the impacts of sludge concentration, stirring intensity and stirring time on the sludge self-flocculation were investigated. Meanwhile, the corresponding variation of the capillary suction time (t_CST), sludge volume index (SVI), particle size and Zeta potential were also analyzed. Experimental results indicated that self-flocculation could enlarge the particle size of sludge and decrease the effect of flocs Zeta potential. Therefore, hydrophobicity, dewaterability and settleability of sludge were improved. Under the optimal self-flocculation conditions (sludge concentration, 18 g/L, stirring intensity, 200 r/min, stirring time, 3.5 min), the particle size and Zeta potential of the sludge increased 11.4% and 19%, respectively, while the t_CST and SVI could be respectively reduced by 17.1% and 8.1%. In addition, the significant effects of operational parameters on self-flocculation showed a decreased trend of sludge concentration > stirring intensity > stirring time. A higher sludge concentration, stirring intensity and stirring time was beneficial to the sludge self-flocculation. However, once each of the three parameters was higher than that at the optimal condition, sludge self-flocculation would weaken gradually. This study provided a new approach for sludge conditioning by using the sludge self-characteristics.