The role of environmental monitoring has become increasingly important. For monitoring and analyzing information of an indoor environment with people, a remote indoor environmental monitoring system is designed and built in this study on the basis of ZigBee technology. Multicast technology is also used to protect this system from interference from other ZigBee networks and ensure the reliable transmission of environmental data. Moreover, a user monitoring platform is designed on the basis of LabVIEW software to realize functions such as real-time display, storage, and over-the-limit warning of monitoring data. Furthermore, the remote communication function is implemented in combination with the Transmission Control Protocol/Internet Protocol (TCP/IP) to eliminate the need to rent a base station or a server, thereby greatly reducing the running cost. In addition, a new monitoring node module has been designed, and the double-sided structure design makes this node more compact. The structural size is only 4.5 × 4.5 cm2. Moreover, a package box suitable for indoor environmental monitoring is also designed and manufactured, such that the node module and each sensor module can be effectively separated and installed. It is small and light, and convenient for the overall installation of this monitoring device. The overall structural size is 12 × 10 × 5 cm3 and the weight is 60.9 g. Finally, this monitoring system has been running for half a year, and comparative analysis of the monitored data and the actual situation showed that this system possesses high reliability and stability.