The invention provides a method and a device for limiting broadcast of an ARP. The method comprises the following steps that: (a) network equipment establishes and maintains a mapping table of IP addresses and bridge ports according to information of the bridge ports which a dynamic IP address distribution related message and a dynamic IP address distribution request message enter, wherein the mapping table of the IP addresses to the bridge ports comprises a plurality of mapping table records; (b) the network equipment extracts an ARP request, and inquires the mapping table according to a target IP address in the ARP request and obtains the corresponding bridge port; and (c) the network equipment unicasts the ARP request to the bridge port. The method and the device can realize the unicast of the ARP request and effectively prevent hacker attacks.