It is a trend to establish a local area network by using the new technology of Bluetooth. This paper discusses the security of establishing wireless local area network with Bluetooth technology, which is mainly divided into two aspects. Firstly, the basic concept and development of Bluetooth technology security and its main defects; Second, discuss security measures, security planning and implementation of security work for different users. Because the data of wireless local area network is sent to the air through wireless media, it is required to have high communication security ability. Wireless LAN can take necessary measures at different levels to ensure the security of communication. First, take appropriate communication measures. For example, using spread spectrum technology makes it difficult for listeners to capture the desired signal from the air; Set the data encryption scheme that users can choose to make it difficult to understand the data content even if the signal is eavesdropped. Secondly, in the same network, strict user passwords and authentication measures should be established to prevent illegal users from accessing the network. In addition, in order to prevent interference and data leakage between different LANs, network isolation measures must be taken.