In this paper, a new method, so-called finite particle method, for form-finding of tensegrity systems is proposed. It models the analyzed domain by finite particles instead of mathematical functions and continuous bodies in traditional mechanics. Examples including simple regular tensegrity systems and complex irregular tensegrity systems are carried out to verify the feasibility and effectiveness of the method. Also a comparison between the proposed method and the dynamic relaxation method is conducted. It proves that the proposed method is much more effective than the dynamic relaxation method in the form-finding of large-scale tensegrity systems. Hence, the proposed method has a great potential of developing into a general and effective form-finding method for irregular and large-scale tensegrity systems.