Provided is a digital signal processor for active noise reduction systems. The traditional passive noise control method achieves good noise reduction effect in middle and high frequencies, but for low-frequency noise, good noise reduction effect can only be achieved by increasing the volume and weight of material as the acoustic attenuation characteristic of passive materials becomes worse with the decrease of the frequency, thus making a project tend to be huge and even difficult to implement. The digital signal processor comprises a housing (9), the housing is internally provided with a microprocessor (1), and the microprocessor is respectively connected with a quartz crystal oscillation circuit (2), an A/D converter (3), a D/A converter (4), a bootstrap memory (5), a program memory (6), a data memory (7) and an I/O interface circuit (8). The digital signal processor is used in active noise control systems.