Abstract: On the basis of analyzing all kinds of tomography fundamental and its advantage and disadvantage, a new multiphase flow detection technique-an electrical impedance tomography is introduced, and a new algorithm used in EIT image reconstruction is proposed.This algorithm will improve the convergence speed and the quality of the image reconstruction by using the method of mixed genetic algorithm and landweber iteration algorithm.The experimental results show that the EIT system is an effective system for multiphase flow measurement, the algorithm has the advantage of good convergence stability and rapid convergence rate.