The present invention discloses a nematocide containing lactonic ring and a preparation method and application thereof. The nematocide containing lactonic ring comprises hydrogen, cyan, fluorine, chlorine, bromine, alkyl containing 1 to 4 carbon atoms, alkoxy containing 1 to 4 carbon atoms, alkoxyphenyl, alkoxy containing 1 to 4 carbon atoms and one or more chlorine atoms in place of hydrogen atoms on the carbon atoms, alkoxy containing 1 to 4 carbon atoms and one or more fluorine atoms in place of hydrogen atoms on the carbon atoms, nitryl, and amido; R 6 is selected from hydrogen, fluorine and chlorine. The present invention has good control effects on the eggs and second-stage juveniles of root-knot nematodes, and especially can well inhibit the hatch of root-knot nematode eggs on cucumbers, tomatoes, tobaccos and soybeans, etc. The nematocide of the present invention has high insecticidal efficacy and can prevent the production of antibodies in pests even after a long time of use. The present invention further provides a preparation method for the nematocide containing lactonic ring. The preparation method has short steps and simple process, and is suitable for large-scale industrial production.