A mal-telecommunicating problem is occurred in a 220 kV substation. After comparing all the possible factors, instead of the traditional reason, the fault is caused by the too much remote communication signals which lead to the overflow of the address message and the overlap of the signals. This analysis provides a new method to mal-telecommunication. For this failure, after considering the economy and maneuverability, deleting or combining redundant signals is chosen as the solution, which improves the accuracy of the remote communication data as well as the security and stability of the automation system.