Preparing method of hydrophilically modified polyvinylidene fluoride ultrafiltration membrane

The invention provides a preparing method of a hydrophilically modified polyvinylidene fluoride (PVDF) ultrafiltration membrane, and relates to the preparing method of the PVDF ultrafiltration membrane. A chemical method is mainly adopted to hydrophilically modify the PVDF ultrafiltration membrane. The preparing method comprises two main steps which are preparation of a polyvinylidene fluoride spinning solution and electrostatic spinning and surface chemical modification respectively. To be more specific, the preparing method comprises the steps of putting PVDF powder into a mixed solution of N-N dimethylformamide (DMF) and acetone with a certain ratio to be prepared to the spinning solution, heating the spinning solution to 40 DEG C and stirring the spinning solution for 1-2 hours until the spinning solution is uniformly mixed, dissolving the spinning solution fully until the spinning solution is of a transparent state, testing and recording the viscosity of the spinning solution, and adopting the electrosta