There are three main production processes for high-density polyethylene: the solution method, the slurry method, and the gas phase method. Among them, the slurry method and the gas phase method have lower reaction pressures, easier-to-control operating conditions, and better product performance. They have now become the most important production technologies for high-density polyethylene in China. Due to the long process flow, high product energy consumption, and high investment of the solution method, almost no enterprises in China choose this method to produce polyethylene.