The theodolite which works on a vehicle has measurement error caused by the deformation of vehicle platform. Two methods that the single error accumulation method and the comprehensive coordinate transformation method to compensate the error were deduced. First, the basic principle of the two methods was analyzed, taking into account the limitations of the different correction methods. Then a practical example with a vehicle platform containing large deformation derivation was built. The measurement error were summarized in two correction methods were compared. The results show that the correct error of the single error accumulation method has several points within large error in whole work scope of the theodolite, caused the error about 5″ larger than the comprehensive coordinate transform method. Therefore the comprehensive coordinate transformation method must be used to obtain high-precision measurements.