The invention discloses an electromagnetic monitoring point distribution method of a same power transmission mode crossing spanning transmission line. The method comprises steps that step 1, a first reference line of a first power transmission line and a second reference line of a second power transmission line of the crossing spanning transmission line are acquired; step 2, a first monitoring distance S1 perpendicular to the first reference line direction is acquired according to intervals of adjacent leads of the first power transmission line, and a second monitoring distance S2 perpendicular to the second reference line direction is acquired according to intervals of adjacent leads of the second power transmission line; step 3, first type monitoring wires of first power transmission wires and second type monitoring wires of second power transmission wires are divided, and crossing points of the monitoring wires of the first type monitoring wires and monitoring wires of the second type monitoring wires are monitoring points of the electromagnetic environment. The method is advantaged in that the optimal monitoring point of the crossing spanning transmission line in the comprehensive electromagnetic environment can be determined, and technical support is provided for accurately monitoring and evaluating an influence degree of the electromagnetic environment.