The invention discloses a method for relay protection simulation based on the short-circuit power directions. The method comprises the following steps that short-circuit calculation is conducted according to fault information so that the short-circuit power direction of each circuit can be obtained; hierarchical topology analysis is conducted in each short-circuit power direction so that a short-circuit power flow direction and protection range value can be obtained; the short-circuit flow direction and protection range value is compared with a preset value and whether protection is started or not is judged; if protection is not started, protection is reverted, and if protection is started, protection starting information is given and added to a protection starting array; protective actions satisfying the requirements in the protection starting array are executed; short-circuit calculation and flow-distribution calculation are conducted so that whether faults are isolated or not can be judged; if the faults are isolated, protection is reverted; if the faults are not isolated, the steps are repeated and fault calculation is conducted again. The method has the advantages of a logical judgment method and a constant value comparing method.