Abstract: In the target detection and identification system, the signal-to-noise ratio between target and background can be improved by using multi-channel filter, so as to achieve accurate detection of target signal. The fabrication technology of multi-channel filter based on nano-imprinting has high requirements for the surface precision and structure precision of the spacer-layer mold. According to the manufacturing requirements of the spacer-layer mold of multi-channel filter array, based on the Single Point Diamond Turning (SPDT), the high-precision manufacturing of the spacer-layer mold is realized by using Fast Tool Servo (FTS). The surface morphology of the mold was detected by using White Light Interference (WLI). The analysis shows that the processing results of the multi-channel filter with 5×5 array structure are in good agreement with the design value, and the accuracy of horizontal dimension and vertical dimension are both better than 5%, which fully meet the design requirements. This technology provides technical support for the large-scale and mass manufacturing of multi-channel filters, and it also provides an effective means for the fabrication of aperiodic array optical elements.