A method for preparing urea ammonium nitrate solution from waste nitric acid after stripping tin from circuit board includes: causing the waste nitric acid after stripping tin and the ammonia water to undergo neutralizing and precipitating reaction through acid-base neutralization, filtering, thereby obtaining tin-containing filter mud and a primary filtrate; adding iron powders into to the primary filtrate to initiate copper-iron replacement reaction, filtering, thereby obtaining iron-containing coarse copper powders and a secondary filtrate; adding hydrogen peroxide to the secondary filtrate, filtering, thereby obtaining an iron-containing sludge and a tertiary filtrate; adding a heavy metal capturing agent to the tertiary filtrate, filtering, thereby obtaining a heavy metal sludge and an ammonium nitrate solution; measuring a concentration of the ammonium nitrate solution, adding urea and liquid fertilizer corrosion inhibitor to obtain a urea/ammonium nitrate dilute solution, evaporating and concentrating the urea/ammonium nitrate dilute solution, thereby obtaining the urea ammonium nitrate solution.