1. A method for recovering lead from lead-containing discarded electronic waste cathode ray tube (CRT) glass, comprising the steps of: taking a sample of cathode ray tube lead-containing funnel glass; crushing the sample to obtain CRT glass powder; preparing a mixture by mixing zero-valent iron powder with the CRT glass powder according to a mass ratio of 0.1-1.5:1; performing heat preservation of the mixture at a temperature of 610-960° C. for 3-180 min; and cooling the mixture to extract the metallic lead from a SiO 2 reticular glass structure of the CRT glass.