Abstract: The basic geometrical relationship of non-cooperative bistatic radar is introduced,and the measuring methods of four parameters (baseline distance, bistatic distance difference, transmitter look angle, receiver look angle), which can compose four distance measuring methods, are discussed. In the condition of considering the error of baseline distance, the error expressions of four distance measuring methods are deduced. The simulation results show that the distance measuring accuracy of each method is relative to the geometrical position of bistatic radar,and the district of highest distance measuring accuracy in space can be achieved by optimization. In practical systems, the selection of distance measuring method should depend on the parameters which can be measured,and the applicable region of each method should be taken in consideration.