The invention provides a method for synchronously obtaining electric signals of any two ends of a power transmission line. The method comprises the following steps of: collecting electric signals uM(t), iM(t), uN(t') and iN(t') of head and tail ports of the power transmission line; calculating a current calculation value iNj(t) of the tail end of the power transmission line at a t moment by voltage and current collection sequences uM(t) and iM(t) at the front end of the power transmission line according to a power transmission line distribution parameter circuit model; calculating a collection time deviation (t-t') of the two ends of the power transmission line according to the current calculation value iNj(t) of the tail end of the power transmission line at the t moment and a collection current sequence iN(t') of the tail end of the power transmission line at a t' moment; and judging whether a collection moment t' of the tail end of the power transmission line is adjusted or not by comparing with a collection time deviation adjusting setting value delta tset. Circularly, the synchronous collection of the electric signals of any two ends of the power transmission line is realized. The method disclosed by the invention eliminates the influences of inconsistency of transmission delay of a data channel of the power transmission line on synchronous collection of the electric signals; and a time block standard signal except for an electric power system does not need to be introduced so that the microsecond-grade synchronous collection precision of the power transmission line can be realized.