Smart grid is a digitally enabled electrical grid system that integrates intelligent power generation, distribution and control. ZigBee network is suitable for smart grid applications, in terms of low cost, low power consumption, low data rate and low complexity. The coexistence of ZigBee networks and wireless local area networks (WLAN) has been convinced to cause significant degradation of ZigBee performance. We propose a multi-channel interference avoidance scheme which can detect interference and adaptively switch to a less interfered channel to avoid WLAN interference. The ”Channel Switching Request (CSR) Transmitting on the Interfered Channel” problem is solved by Multi-channel communication, thus increasing transmission reliability of CSRs. Experimental result shows that, compared with conventional channel switching algorithm, our scheme efficiently improves success rate of channel switching, and mitigates the effect of WLAN interference.