It is well-known that polymer composites containing conductive fillers become conductive when the filler content exceeds a critical value, named percolation threshold (pc) owing to the formation of conductive networks. Many methods have been proposed to reduce pc and ensure good electrical conductivity of the conductive polymer composites (CPCs). But inevitably, these methods to reduce pc are often accompanied by the sacrifice of mechanical property and process-ability of the CPCs. Therefore, it has been paid more attention to maintain or even improve the strength of CPCs when excellent electrical property is remained at the same time. In this work, the electrical conductivity and strength of polypropylene/nickel coated glass fiber (PP/NCGF) composites are enhanced simultaneously via a simple strategy by using nucleating agent induced crystallization. The incorporation of nucleating agent dibenzylidene sorbitol (DBS) extends crystalline region and refines grains of PP matrix, which leads to the sharp volume excluded effects and confines the NCGFs within the amorphous region, and thus the formation of conductive network connected by NCGFs is promoted. Accordingly, the percolation threshold of PP/NCGF composites is decreased to 0.35 vol% (Ni content) by loading DBS, and the conductivity increases by four order of magnitude around the percolation threshold which exceeds 70 S/m with the Ni content of only 0.47 vol%. The tensile strength of PP/NCGF composites is improved by about 30-40 % in all range of NCGF content due to the enhanced crystallinity and the reinforced interfacial interaction. This exciting result provides a strategy to prepare high-performance conductive composites by crystallization-induced enhancement.