There is a critical need for the rapid detection of p-chlorophenol produced by pesticide abuse and industrial wastewater discharge, which has been an urgent problem in the realm of environmental protection. Here, a green and environmentally friendly method was developed to prepare stable and low toxicity quantum dots. First, blue-green fluorescent FeS2 quantum dots (B-FeS2 QDs) were prepared with FeCl3·6H2O (an iron source) and L-cysteine (a capping agent) by the solvothermal method. By combining B-FeS2 QDs with orange carbon dots (O-CDs), a CDs@SiO2/FeS2@MIPs visual fluorescence sensor for the selective detection of p-chlorophenol was constructed. Under optimum conditions, this sensor exhibited a detection limit of 1.265 μM with a linear range of 5.00-50.00 μM and was successfully applied to detect p-chlorophenol in real samples. Moreover, this sensor was successfully applied to visual semi-quantitative detection of p-chlorophenol. This work demonstrated that these sensors, based on FeS2 QDs and CDs, had potentials for in situ and visual detection of environmental contaminants.