The invention firstly discloses N-acyl-1,2-cyclo-nitrogen-p-menthane, as well as a preparation method and herbicidal activity application thereof. The preparation method comprises the following steps: dissolving N,N'-diacyl-1,8-p-menthane diamine or N-acyl-3-poxlene-1-amine into a strong acid water solution, stirring, and carrying out a reaction under the appropriate temperature condition for 20 h or longer; after the reaction is finished, allowing the reaction liquid to cool and stand still, and stratifying the reaction liquid; adjusting the pH of the lower layer solution to be 8-11 through a sodium hydroxide water solution, and stratifying the solution, wherein the upper layer is yellow transparent liquid; conducting vacuum drying on the upper layer yellow transparent liquid, and purifying through silica gel column chromatography to obtain N-acyl-1,2-cyclo-nitrogen-p-menthane. The product is relatively mild in reaction condition, simple in technology process and easy for raw material preparation, and is very beneficial to development and utilization. The prepared series of N-acyl-1,2-cyclo-nitrogen-p-menthane plays a better growth inhibition effect on annual ryegrass.