To solve the problems existing in the pilot scale production of water-soluble polymer coated fertilizer using the fluidized bed coating machine, this study was performed on effects of cross-linker dosage on surface structure and hydrophobicity of the coating and effects of different post-processing techniques on performance of controlled release. Results showed that when the cross-linker (aziridine) added into the water-soluble-polyacrylate-latex-dominated coating material, increased from a rate of 1% to the rate of 2%, surface structure of the fertilizer coating became smoother and denser, as well as higher hydrophobicity. Consequently, the coating performed much better in controlling nutrient release. When the two coated fertilizers different in cross-linker rate (1% and 2%) added into the coating material were soaked in still water at 40℃ in temperature for 9 days, it was found that the former released more than 90% of the total nutrients, whereas the latter just released about 40%. However, the performance varied with different post-coating treatment, and it was much better when the coating was oven-dried than when it was microwave-dried. When the coating was low in cross-linker dosage (0.3%), higher processing temperature (60℃-80℃) significantly improved its performance, but when the coating was high in cross-linker dosage (> 1%), raising temperature almost did not have much effect.