Selecting and blocking ball for performing profile control of water injection well in medium-high temperature oilfield and preparation method and application thereof

The invention provides a selecting and blocking ball for performing profile control of a water injection well in a medium-high temperature oilfield and a preparation method and application thereof. The selecting and blocking ball is manufactured by a mixture of polyvinyl chloride and high-density polyethylene. The preparation method comprises the steps of heating polyvinyl chloride and high-density polyethylene in a mixing mode to form a melt, or heating polyvinyl chloride and high-density polyethylene to be the melt and mixing; and manufacturing solid-state selecting and blocking ball products with different diameters. The selecting and blocking ball can be applied to blocking of shot holes in fractionized water injection sections of the water injection well in the oilfield, so that the water injection effect can be improved to increase the yield of crude oil exploitation and oil extraction efficiency.