Abstract: Cypermethrin is one of the most highly used pyrethroid insecticides globally and is potentially a threat to soil organisms such as earthworms. In this study, the earthworm was selected as a test organism to design a test on the effect of cypermethrin low-dose exposure on the memory damage of earthworms. The results indicated that cypermethrin exposure not only inhibited Na⁺-K ⁺ -ATPase and other enzyme activities characteristic of nerve ion channels in the earthworm brain, but also caused memory impairment in earthworms. The integrated biomarker response (IBR) values of the cypermethrin 2 and 6 mg/kg treatment groups were 2.4 and 9.5 at 28 d of exposure, while they were 4.4 and 11.4 at 56 d of exposure, respectively. The bigger the exposure concentration and the longer the exposure time, the more serious the degree of memory impairment of earthworms caused by cypermethrin.