Distribution generation(DG) of oilfield based on associated gas has the dispersive characteristics and is of small capacity, which is treated as PQ point in power flow calculation according to load control type. A distribution network reconfiguration algorithm based on simulated annealing and immune algorithm is proposed in this paper, where the annealing operator simulated by Boltzmann is used in selection operation, and the method of immune vaccine is applied for improving the diversity and convergence performance of population. In order to avoid the infeasible solutions in evolution, a method of public switches matrix of loops is proposed, and the searching space is compressed effectively. The tested system shows the advantages of given method, and great benefits can be obtained in oilfield application.