A solid-free anti-hydrogen-sulfide low-damage well washing fluid and a preparation method are provided, the solid-free anti-hydrogen-sulfide low-damage well washing fluid overcomes the drawbacks of incomplete sulfur removal, formation pollution, and yield reduction of washing fluid added with a sulfur elimination agent and high concentration hydrogen-sulfide-containing wells, the solid-free anti-hydrogen-sulfide low-damage well washing fluid comprises the following components by weight: 80 to 95 parts of water, 1.6 to 2.85 parts of potassium chloride, 0.4 to 0.6 part of sodium metaborate, 0.16 to 0. 285 parts of sodium perborate, and 0.1 to 0.3 part of sodium dodecylbenzenesulfonate. The beneficial effects are as follows: the solid-free anti-hydrogen-sulfide low-damage well washing fluid is good in stability, high in hydrogen sulfide absorption concentration, and free of solid phase component, can effectively prevent the reservoir pore throat blockage, is good in formation water and reservoir rock compatibility, may not cause reservoir pollution and yield reduction, can provide a good alkaline environment, and ensures construction safety.