The invention discloses a link state monitoring and fault removing method of multi-home hosts, and the method comprises the following steps: a host identification protocol (HIP) is expanded, an accessibility maintenance time parameter and two types of notification parameters with unavailable accessibility maintenance and addresses are introduced, thus enabling a host which initiates the communication and a peer host to determine timing numerical values of sending timers respectively, and in an initial stage of link state monitoring, the accessibility maintenance time parameter is used to negotiate and determine the timing numerical values of address maintenance timers respectively; in a communication process, according to the notification parameter of the accessibility maintenance type and the two negotiated timing numerical values of the sending timers and the address maintenance timers, hosts at two ends monitor the communication link state; when a fault occurs, the hosts at the two ends select different working modes and use the notification parameter of the address unavailability type and three-way shaking and updating processes of the HIP protocol to remove the fault and recover the communication, thus monitoring the link state in a multi-home scene rapidly and efficiently and removing the fault in time.