Abstract: With the development of smart distribution network, the requirements of fault recovery are also improving. How to achieve rapid, accurate and effective fault recovery has attracted people's attention. In view of the rapid, accurate and efficient response of biological immune system matching the requirements of fault recovery, this paper combines it with smart distribution network to establish smart distribution network fault recovery method based on biology immune mechanism, which provides a new idea for power supply after failure. Firstly, the "electronic dictionary" is used to describe the characteristics of faults and immune matching is carried out. Then, the existing scheme is used to restore the power supply for the successfully paired fault. Otherwise, the fault is processed by the first immune response model. At the same time, in order to improve the proportion of secondary immune response, the immune memory model is proposed to construct contingency set, and the pre recovery scheme of high-risk fault is simulated to expand the immune memory cell bank. Finally, a modified actual distribution network is simulated, the contingency set and decision set are given, a real fault is simulated and matched, and the recovery schemes after failure in different periods are given. The reliability index of the traditional recovery decision method is compared and analyzed with this method.