The projection display subsystemThis article focused on the two multi-channel system splicing technology, which are flat-panel screen and ringscreen, and also given the realization method. Established a distributed communication environment by selecting TCP protocol ,the multi-channel systems are optimized by adding the maximum relevant waiting time for the communication process between the Master-side and the Slave-side, achieved a large-screen multi-channel 3D display system, gives a passive multi-channel 3D display system hardware solutions. The experimental results show that the system has a good performance on the real-timing, consistency and the display. .