Internet of things (IoT), combined with various backbone transmission, is very suitable for remote real-time monitoring. However, along with the expansion of monitoring scope and popularization of the application, the cost and impact caused by system interruption is increasing rapidly. Reliability of system topology is very important in guaranteeing the reliability of remote monitoring system. Taking the actual demand of setting up monitoring region for the IoT-based Three-River Source region remote monitoring as background, this paper proposes a scalable uniform clustering based modular sensor deployment method, and gives calculation formula for the relationship between the layer number of topological architecture, the monitored area and the sensor number. To address the unstable information transmission environment, this paper presents an effective mechanism and quantitative analysis method to guarantee the reliability of monitored region and remote backbone topology. This method highlights a dynamic optimization strategy to the topological reliability of those key transmission nodes. Theoretical analysis and simulation results show that this method is placed on traits such as even data fusion, effective energy saving and extensibility and is remarkable in improving the reliability of IoT-based remote monitoring. At the same time, theories from this paper have important theoretical and actual application reference value in guaranteeing topological reliability of IoT-based remote real-time monitoring of large region, such as agriculture, animal husbandry and forestry related industries.