Abstract: With the development of radar and tracking technologies,the mode of orbit tracking and telemetry control system is evolving towards a new type of using only six or more velocity-measuring radars.As a result,it is necessary to study problems such as data processing in the new system,and the priority of various algorithms in this new system.Error propagation theory was used to compare the accuracy of point by point algorithm and that of the polynomial algorithm so as to provide theorefical supporting for the use of polynomial and spline algorithm in the new system.Computer simulations by using the two algorithms for two typical orbits were presented.It showed that the polynomial algorithm can get much higher accuracy than the point by point algorithm,besides,data structure of the polynomial algorithm was simple and suitable for real-time computation.