The invention discloses a recovery method of diamond. The recovery method solves the problem that in the prior art, a large amount of waste gas and wastewater is generated during the production process. The recovery method is characterized by comprising the following steps: at first, adding waste diamonds and water into a reactor according to a mass ratio more than 1: 3.15 of waste diamonds to water; under a controlled pressure, introducing chlorine gas to corrode the metals; after corrosion reactions, filtering to obtain diamonds and filtrate; extracting copper from the filtrate, evaporating the filtrate, concentrating the filtrate, extracting metal salts from the filtrate; and cyclically using the water, which is obtained by condensing the steam generated during the process of evaporation and concentration. The provided technology does not generate insoluble gas and water, the acid solution does not contain any water, and thus the problem that a large amount of waste gas and wastewater is discharged is solved.