The handoff process specified in 802.11 is time-consuming, and the strategy of choosing AP based on the received signal strength often fails to meet the mobile station’s bandwidth requirement. Therefore, 802.11 is unsuitable for industrial robots which have to rely on uninterrupted communication to work. This study proposes a fast handoff technology based on dynamic WiFi map that can provide bandwidth guarantee for mobile industrial robots. A prebuilt WiFi map is used to help the robots obtain their nearby Access Points (APs) without channel scanning, and at the same time, a server is used to collect the workloads of all APs periodically and provide robots with AP selection service that tries to meet both low handoff delay and bandwidth guarantee. This study implements the proposed fast handoff technology on a famous network simulation platform NS3 and compares it with some existing handoff schemes. The experimental results show that the proposed handoff scheme is superior to other handoff schemes in all cases, and can always choose the best APs with bandwidth satisfaction as long as there exists APs in the vicinity of the robot that have sufficient bandwidth.