Remediation system and remediation method for heavy metal contaminated soil and underground water

The invention provides a remediation system and method for heavy metal contaminated soil and underground water. The remediation system comprises an eluting agent liquid storage tank which is located outside a contaminated soil layer; an eluting agent liquid injection pipe which is connected with the eluting agent liquid storage tank, has a free end extending into the position between the contaminated soil layer and an underground water layer, and is provided with a plurality of spraying structures on the side wall thereof at intervals; an underground water return pipe which is connected with the eluting agent liquid storage tank, and has a free end extending into the underground water layer; and an adsorption device which is arranged on the underground water return pipe and is used for purifying water flowing through the underground water return pipe. According to the remediation system and remediation method for heavy metal contaminated soil and underground water, comprehensive remediation treatment can be c