With the wide deployment of wireless local area networks (WLANs), the problem of configuration and maintenance of access points (APs) arises. The traditional manual configuration method greatly increases the cost of configuration and maintenance of the WLANs system and hinders the scalability of WLANs. The plug-and-play (PnP) of APs, which means that APs auto-configure themselves based on the network environment, is a good solution to this problem. The PnP of APs can reduce both the complexity and cost of configuration and maintenance for WLANs and also improve the system performance. The selection of working mode and channel is one of the major challenges for the PnP of multi-mode APs. In this paper, we propose a mode and channel selection scheme that combines analytic hierarchy process (AHP) with grey relational analysis (GRA). The goal of our proposed scheme is to select the most suitable mode and channel for multi-mode AP to improve the performance of WLANs and offer better service to users. In the proposed scheme, AHP is responsible for deciding the weights of criteria factors according to their contributions to the final goal. GRA combines the weights of criteria factors with the values of criteria factors to rank all alternative modes and channels combination and make a decision. It is seen from the simulation results that our proposed scheme can select the most suitable working mode and channel for AP in different scenarios.