Electrical discharge machining (EDM), as an effective method, can be used to implement the finish machining for turbine blisks. Searching an interference-free path for feeding an electrode through twisted tunnels of a rimed blisk was carried out. Based on the approach coefficient of free surface defined, the electrode kinematic constraints and object function were determined. The two-step path searching is applied for searching the interference-free path. Finally, the path searching algorithm is verified with an example.