Abstract: To overcome the external conditions affected by the analog circuit's chaotic system, a method of designing fractional-order chaotic system based on DSP Builder is proposed.Taking the fractional-order Jerk system as an example, a difference method of first order is adopted and the dynamic characters of fractional-order chaotic system can also be analyzed.The simulate results show that the design method for fractional-order chaotic system based on DSP Builder is efficient.The digital realization of the fractional-order chaotic system has been provided a new way.