The invention discloses a concentrated combustion type in-situ thermal desorption repairing method for a contaminated site. A concentrated combustion type in-situ thermal desorption repairing device is arranged and used for conducting repairing. The concentrated combustion type in-situ thermal desorption repairing device comprises a combustion heat transferring and waste heat recovery unit, an extraction condensation and gas-liquid separation unit, an underground water flow control unit, a soil gas control unit, a waste gas treatment unit and a waste water treatment unit. The combustion heat transferring and waste heat recovery unit comprises an air heating furnace, a gas-gas heat exchanger, an air blower, an induced draft fan, an exhaust funnel and a heating well group. The extraction condensation and gas-liquid separation unit comprises an extraction well group, heat exchanging and condensation equipment, gas-liquid separation equipment, a demist tower and a vacuum pump. The waste gas treatment unit comprises adsorption equipment and a draught fan, and the waste water treatment unit comprises an adjusting pool, a combination pool, sand filtering equipment, carbon filtering equipment and a water outlet pool. According to the concentrated combustion type in-situ thermal desorption repairing method for the contaminated site, defects of the prior art can be overcome, and a betterrepairing effect is achieved.