Electrical Impedance Tomography（EIT）

a new image reconstruction technique

is being developed after X-CT and MRI.Based on mathematical physical model

an algorithm called alternate algorithm of gradient-memory descent direction is proposed in this paper.Compared with popular algorihtms about EIT

it has advantages of high convergent speed

good inner discrimination and independence from initial value.The computer simulation result shows this algorithm converges on the theoretical solution at an exellent precision.The result is also satisfactory even when the measure data involve 5% random error and 5% shift error.