Classical methods for initial orbit determination (IOD) include Laplace method, Gauss method and their variations. In addition to this, based on the characteristic of optical observation data nowadays, experts propose some other IOD methods, like Double-r method and admissible region method. One of the ways to determinate the orbit through double-r method is to guess distances of the target from the observer at two epochs---usually at the first and the last one. By doing so, we can solve the Lambert problem and use its solution as the initial guess of the orbit. Furthermore, we can improve the initial guess by iterations to reduce the root mean square (RMS) of the observations. The admissible method is based on the concept of attributable (longitude, latitude and their rates). With some conceptions, the admissible region described by the range and range rate from the observer is characterized. Using triangulation we can find the nodal point that makes the RMS minimal. In our work, we apply one intelligent optimization method---the particle swarm optimization method to the two methods, based on simulated and real data, and compare the results with that of modified Laplace method. At last, we briefly discuss the possibility of applying the double-r method to the orbit link problem.