Abstract: Objective Responding to the disadvantages existing in the total least squares algorithm(TLS),thevirtual observation method is employed to transform the TLS into a classical least squares algorithm(LS).Then,a matrix vectorization formula suitable for three-dimensional coordinate transformationis deduced.In this way,unification of LS and TLS is realized.As compared to other algorithms,thismethod has a stricter theory and simpler calculation process.A numerical test proves that a more rea-sonable transformation result can be obtained by using this method.