The invention relates to a preparation method and coating method of a biodegradable temperature-responsive slowly-controlled release fertilizer coating material. Agricultural organic waste containing cellulose serves as the raw material and is crushed, sieved, modified with dopamine and subjected to enzyme activation secondary treatment, and activated powder is obtained; the activated powder is mixed with a thermo-sensitive poly phosphate ester monomer, an initiator and a beta-cyclodextrin accelerant, the mixture is heated and stirred, a free radical polymerization reaction is conducted under protection of the inert gas, and the biodegradable temperature-responsive slowly-controlled release fertilizer coating material is obtained after vacuum drying is conducted; and the biodegradable temperature-responsive slowly-controlled release fertilizer coating material is heated to be a molten state and smeared on surfaces of fertilizer particles in a coating machine, and coated slowly-controlled release fertilizer can be obtained. Dopamine-activated agricultural organic waste is adopted from the angle of bionics, a polymerization reaction is effectively promoted in combination with enzyme activation secondary treatment, and production efficiency is improved; and meanwhile, the thermo-sensitive poly phosphate ester monomer serves as a cross-linking agent, the beta-cyclodextrin serves as the accelerant, and polymerization reaction time is shortened, so that the fertilizer intelligently regulates and controls nutrients along with soil temperature change.