该文在大量测试实验和理论分析的基础上，研究电磁波在楼内公共烟道的传输问题，分析公共烟道环境的特殊性以及影响电磁波传输损耗的因素。提出一种适用于楼宇集中净化物联网系统的基于SX1278的无线传输方案。该方案采用直接序列扩频调制来提高系统的抗干扰性能，采用截断二进制指数退避算法作为重传机制来解决节点信号冲突碰撞问题。通过在基站端采用时间片轮转调度，来保证计数的同步性和实时性。集成测试和实地测试结果表明，该方案很好地解决了烟道内无线信号的稳定传输问题，且丢包率和误码率较低，系统可靠性好。-On the basis of experimental and theoretical analysis of a large number of tests on the study of electromagnetic waves in the building of public flue transmission problems, analyze the particularity of public flue environment and factors affecting the electromagnetic transmission loss. Is proposed for building things centralized purification system based on wireless transmission scheme SX1278' s. The program uses direct sequence spread spectrum modulation to improve anti-interference performance of the system, using the truncated binary exponential backoff algorithm as the retransmission mechanism to resolve conflicts node signal collision. The base station side by using round-robin scheduling to ensure counting and real-time synchronization. Integration testing and field test results show that the program solves the problem of stable transmission of radio signals within the flue, and the packet loss rate and the error rate is low, better system reliability.