New energy power stations on a large scale clustering to connect to power grid, not onlyincreases the probability of cascading failure, but also deteriorates the power grid operation status after failures. Considering the new requirements of the power grid operation analysis, based onrunning conditions of new energy units and reactive power compensation devices, researches asimulation method using to forecast cascading failure path of new energy power station groups.Through the simulation calculation example analysis based on the large power grid data, acquires the detailed cascading failure path of a certain new energy power station under the typical constraintcondition. The researche result shows that: the simulation model based on actual condition of newenergy units, suits simulation forecast for cascading off -line failure path of new energy powerstation groups.