The invention discloses a pesticide contaminated soil treatment device adopting an advanced oxidation technique. The pesticide contaminated soil treatment device adopting the advanced oxidation technique comprises a reaction cylinder, a leachate collection tank, a reflux pump, a water distributor, an ultraviolet lamp, an acid solution adding mechanism and a hydrogen peroxide adding mechanism, wherein a flow guiding layer, a mixing layer and a magnetic nano-material layer are sequentially arranged in the reaction cylinder from bottom to top, and a flow guiding port is formed in the lower portion of the reaction cylinder and located below the flow guiding layer; a leachate inlet of the leachate collection tank is connected with the flow guiding port; an inlet of the reflux pump is connected with a leachate outlet of the reflux pump; the ultraviolet lamp is located above the reaction cylinder; the acid solution adding mechanism can add an acid solution onto the magnetic nano-material layer; and the hydrogen peroxide adding mechanism can add a hydrogen peroxide solution onto the magnetic nano-material layer. According to the pesticide contaminated soil treatment device adopting the advanced oxidation technique, the treatment period is short, the treatment cost is low, and the treatment effect is good.