Dominant electroactive phases (β- and γ-phase) are induced in poly(vinylidene fluoride) (PVDF) by simply melt-blending with a small amount of quaternary phosphonium salts (QPS), required no organic treatment for regularly-used inorganic nanofillers. Two kinds of QPS with similar structure are selected to investigate the correlation between crystallization kinetics from melt and electroactive phase formation of PVDF and nearly 100% electroactive phase is achieved. Tetraphenylphosphonium bromide (TPPB) can effectively increase the crystallization rate of PVDF and initiate the PVDF crystallize into γ-phase directly from the melt. Smaller amount of tetraphenylphosphonium chloride (TPPC) added into PVDF matrix achieves an abrupt increasing of the crystallization rate and cause the PVDF trends to crystallize into β-phase. On the analysis of Hoffman–Lauritzen (LH) model, the crystallization regime II disappears or moves to higher temperature where the crystal growth rate is controlled by segmental diffusion rate together with the secondary nucleation rate. These results can be attributed to a stronger interaction between the TPPC nanoparticles and PVDF chain segments than TPPB. The inductive mechanism of TPPB and TPPC on PVDF polymorphism behavior is also researched. When the PVDF chain segments nucleate and fold into the crystals, a type of interaction occurs between the CF2 dipoles on PVDF chain segments and the positively charged phosphorus atoms on the QPS molecules. Consequently, this interaction restricted the PVDF molecules rotations and more TTTT conformations are formed on the PVDF chains during the nucleation and crystal growth process in the TPPC/PVDF melt-blending system.