Heat-shrinkage-resistant and puncture-resistant polyolefin diaphragm material and preparation method thereof

The invention discloses a heat-shrinkage-resistant and puncture-resistant polyolefin diaphragm material and a preparation method thereof, and belongs to the technical field of polyolefin diaphragms. The polyolefin diaphragm material with heat shrinkage resistance and puncture resistance is used for solving the technical problems that in the prior art, the compatibility between a polyolefin composite diaphragm and an electrolyte is low, and the heat resistance of the polyolefin composite diaphragm is poor. The composite material is a mixed raw material consisting of the following components in parts by weight: 20-30 parts of modified polyolefin, 10-20 parts of modified ethyl cellulose, 20-30 parts of high-density polyethylene, 0.2-0.4 part of an antioxidant, 0.1-0.3 part of a nucleating agent and 0.1-0.2 part of a dispersing agent. The polarity of the polyolefin composite diaphragm can be effectively improved, the compatibility between the polyolefin composite diaphragm and an electrolyte is promoted, the impe