When
S > 400m,
b> 5 (
bs/
n) and the certain relationship of
fa~
s,
fa~
b,
fs/[
s]~[
s] and
fs/[
s]~
b are exist, the best results under the same observing precision are obtained. Above conclusions are proposed based on the studies to the results of 33 distance surveying wires of annexed electromagnetic wave. The optimum value of[
s] and
n, the selection of begining azimuth is also proposed in this paper, it has some reference value for surveying of annexed wire.