Non-adaptive transformations are effective in calculating the propagations of the focused laser beams. The usual non-adaptive transformation is based on the free-space propagation properties of the Gaussian beams. In this kind of transformation, the shape and the size of the Gaussian beam will be reserved, while the focused spot sizes of other kinds of beams, such as uniform wave, will increase with the increase of the focal length so that the beam will collide with the boundary of the calculation field. In this report a new kind of non-adaptive transformation is adopted in which the shrink of the calculation field will depend on the real size of the focused beams.