The existing curve-drawing algorithms are single step. A double-step commonly used algorithm for drawing curves is presented in this paper. In each step of the algorithm two pixels are drawn. As an example, the realization process for cubic Bezier curve is given. A pseudo code of the algrithm is given. The results of the calculation comparison between the algrithms are given. The results show that the calculation of the proposed double-step algorithm is much less than that of the single-step algorithm.