Abstract: Multifractal theory is an effective tool for the singularity processing of signal, but only a few special sets have analytic multifractal spectrum expression. The calculation of multifractal spectrum is important and difficult. This paper introduces one of the formal system of multifractal theory in brief and presents an approach to calculate the multifractal spectrum of general sets. The approach makes use of the dynamic link data structure and decreases greatly the demand for memory. By means of the approach , the multifractal spectrum of Cantor set is calculated. The result is in accordance with the theory analysis and shows that the presented algorithm is valid.