The invention discloses a method for transmitting positive and negative data across a 
safety zone, which is applied to message transmission of a power scheduling automatic 
system across the 
safety zone. A communication mechanism which combines positive communication with negative communication is used for forming a complete communication loop for message interception and 
message forwarding. The invention provides a 
safety zone crossing communication method which is suitable for the communication mode of combining positive communication with negative communication across the safety zone in a power 
system, and is used for realizing bidirectional interactive transparent forwarding by combining network message interception and a positive and negative forwarding program, realizing 
shunting of different service messages under 
service quality control and increasing the running efficiency. 
System integration complexity is simplified, a positive message transmission process and a negative filetransmission process which are originally independent of each other are connected in a seamless way through a program, and communication between application programs across the safety zone is as convenient as that in the same safety zone. Moreover, basis is provided for accurate positioning of 
retransmission messages, the quantity of 
retransmission messages is reduced, and the communication reliability is enhanced.