According to the several mal-operation accidents of zero-sequence pilot protection happened recently in the high-voltage power network due to the influence of zero-sequence mutual inductance between power lines， this paper analyzes the typical power network topologies with magnetically strong and electrically weak connection that caused the mal-operation. The influence of zero-sequence mutual inductance on the behaviors of zero-sequence pilot protection is studied in detail and several countermeasures are analyzed. A new type of zero-sequence directional relay based on fault type is proposed and the feasibility and detail scheme flow are described. The scheme is validated to be correct by the data analysis of two local examples.