We describe a facile and novel method for preparing highly dense Langmuir–Blodgett (LB) nanofilms of poly(vinylidene fluoride) (PVDF) with precisely adjustable film thickness from several to hundreds of nanometers, assisted by amphiphilic poly(N-dodecylacrylamide) (pDDA) nanosheets. Even at a molar mixing ratio of PVDF:pDDA up to 50:1, the high collapse surface pressure of 44.4 mN/m obtained using this method is a breakthrough for the preparation of PVDF LB nanofilms, which is devoted to the resulting high-density PVDF nanofilms. As shown by FTIR and XRD measurements, the mixed LB nanofilms without any postprocessing comprised dominant ferroelectric β phase of ∼95% and negligible paraelectric α phase. Furthermore, through control of the surface pressure, controllable PVDF crystal morphologies were achieved. Moreover, β phase PVDF dominates in all cases. After applying a dc bias of 5 V through a conductive cantilever, the local polarized pattern on the surface of a nine-layer mixed LB nanofilm observed usi...