TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The water is distilled water or de-ionized water. The concentration of hydrochloric acid solution is 1 mol/L.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): A polyhydroxyethyl methacrylate is prepared by:(A) mixing initiator, monomer, catalyst, aglucon and organic solvent, removing oxygen of reaction system, introducing argon for 10 minutes, sealing, reacting for 5-24 hours at 20-100 degrees C, centrifuging the reaction product to obtain precipitate, washing the precipitate, and obtaining a first compound;(B) dissolving first compound in organic solvent, adding hydrochloric acid solution, reacting for 3-12 hours at 30 degrees C, centrifuging the reaction product to obtain precipitate, washing the precipitate, and obtaining second compound;(C) dissolving the second compound in organic solvent, adding triethylamine and cinnamoyl chloride at 0 degrees C, reacting for 3-12 hours at 20-50 degrees C, centrifuging the reaction product to obtain precipitate, washing the precipitate, and obtaining a third compound;(D) dissolving third compound in organic solvent, adding triethylamine and bromination reagent at 0 degrees C, reacting for 3-12 hours at 20-50 degrees C, centrifuging the reaction product to obtain precipitate, washing the precipitate, and obtaining a fourth compound;(E) dissolving the fourth compound in organic solvent to obtain polymer solution, soaking hydrophobic porous film in polymer solution for 3-12 hours, irradiating the polymer solution soaked with the hydrophobic porous film under UV light for 0.5-2 hours, allowing the hydrophobic porous film out, cleanly washing the residual polymer solution on the hydrophobic porous film to obtain a composite film; and(F) allowing composite film to mix with methacrylic acid dimethylamine ethyl ester, catalyst, aglucon and organic solvent, removing oxygen of the reaction system, introducing argon for 10 minutes, sealing, reacting for 5-24 hours at 30-100 degrees C, adding hydrochloric acid solution to soak for 3-12 hours, washing the reaction product by using water and removing hydrophobic porous film in water to obtain polyhydroxyethyl methacrylate.The mol ratio of initiator to monomer to catalyst and to aglucon is 1:(1-400):(1-10):(1-10). The initiator can be 4-bromoethyl benzophenone or 1-phenylethyl chloride. The monomer is hydroxyethyl methacrylate or hydroxyethyl acrylate. The mol ratio of second compound to triethylamine and to cinnamoyl chloride is 1:(0.3-0.7):(0.3-0.7). The mol ratio of the third compound to triethylamine and to bromination reagent is 1:(1-5):(1-5). The hydrophobic porous film can be polypropylene, polyvinylidene fluoride, polysulfone, polyethylene or polyether sulfone. The mass ratio of composite film to hydroxyethyl methacrylate, to catalyst to the aglucon and to the organic solvent is 1:(10-100):(0.1-1):(0.1-1):(10-100). The catalyst is cuprous chloride or cuprous bromide. The aglucon is 2'2-bipyridyl or pentamethyl diethylenetriamine. Preferred Component: The mass ratio of monomer to organic solvent is 1:1. The volume ratio of hydrochloric acid solution to organic solvent is 1:100. The bromination reagent is 2-bromine isobutyryl bromide. The mass ratio of hydrochloric acid solution to organic solvent is 1:50. The organic solvent is N'N-dimethylformamide, acetonitrile, tetrahydrofuran, benzaldehyde, methylbenzene, dioxane, pyridine or methanol.