An algorithm to finding the k-nearest neighbors of points is provided quickly which is based on the space character of data-points. Data set is queued by multilinked list. By using envelopment-space, the range of data set , the total numbers of points, the searching step and the numbers of nearest neighbors, the method is easy to obtain the value of e and k for a nearly optimal searching. By improving the terminate rule of searching, this method has some excellent characters such as shorten searching range and quicken speed.