A one-dimensional nano-positioning control system based on a controller using DSP (Digital signal processor) chip was developed. The system was mainly composed of a driving stage, a miniature Michelson interferometer and a DSP controller. The driving stage module included a linear stage, an ultrasonic motor HR4 and a motor driver AB2. The HR4 and AB2 were used to drive the ceramic strip adhered to the side of the linear stage by friction. The miniature Michelson interferometer was used to detect the displacement of the stage. Both the PID control algorithm based on BP neural network and the signal processing of the Michelson interferometer were finished by the DSP controller. The experimental results show that the positioning accuracy of the nano-positioning system is better than 10 nm within 20 mm range, and the standard deviation of repeated positioning is 7 nm. The positioning system has the advantages of simple structure, high positioning accuracy, and can be used on the occasion of high-precision positioning.