The invention discloses a thiosemicarbazide-bonded PDA@MWCNTs adsorbent and a preparation method and an application thereof, which belong to the technical field of composite adsorbing materials. The point of the technical solution of the invention is that the thiosemicarbazide-bonded PDA@MWCNTs adsorbent is prepared by using hydrogen peroxide to oxidize polydopamine and further bonding thiosemicarbazide. The invention further specifically discloses a preparation method for the thiosemicarbazide-bonded PDA@MWCNTs adsorbent and an application of the thiosemicarbazide-bonded PDA@MWCNTs adsorbent in separating and enriching gold from waste circuit board metal concentrate aqua regia leachate. The conditions of the preparation process disclosed by the invention are mild, the preparation process is easy to operate, the prepared thiosemicarbazide-bonded PDA@MWCNTs adsorbent has the advantages of high adsorption rate, high adsorbing capacity and high selectivity, and is applicable to the separation and enriching of gold from complex gold-containing solutions, such as waste circuit board metal concentrate aqua regia leachate.