In terms of low accuracy of fast Hankel transform algorithm, modified-continued fraction algorithm was used to simulate sine or cosine transform, and compared the results with the digital filter (DF) algorithm’s , which shows that when dealing with fast convergent sine transforms or divergent transforms that DF method failed to calculate accurately here, the modified continued fraction algorithm has always a high precision and quite stable results. Then some typical ATEM 1-D modeling problems were calculated by this algorithm, and the results ,which was compared with that by DF algorithm that was based on fast Hankel transform, were quite satisfactory in terms of its accuracy, speed and stability, the result show that this algorithm is a new efficiency method for calculation of transient electromagnetic modeling .