Transparent transmission is one method of transferring Ethernet data so that it is only responsible forsending business data to destination nodes without regard for the underlying protocol or preprocessing of data properties and content. The program uses Nios II, which is integrated into field programmable gate arrays as the control element. By transplanting μC/OSII realtime operating systems, using NicheStack TCP/IP protocol stacks, packets were captured and forwarded on the data link layer transparently between wireless laser communication system and the Ethernet. The data consistency of the design is tested by system simulation, circuit experiment and optical experiment. Our test results showed that the scheme performed transparent transmission well.