A linear protection method for an optical network, used for protecting a failed service path in the optical network, the method comprising the following steps of: A. setting priorities of services carried on service paths participating in linear protection of the optical network as service priorities; and B. selecting, from the service paths participating in the linear protection, a service path of which the service priority is lower than that of the failed service path as a protection path, and bridge switching the service on the failed service path to the protection path; characterized in that: the method further comprising the following step before step B: configuring fixed priorities for the service paths participating in the linear protection of the optical network and setting the service priorities of the service paths to be equal to the fixed priorities; wherein the step B comprises: selecting, from the service paths participating in the linear protection, a service path, of which the service priority is lower than that of the failed service path and meanwhile is the lowest, as the protection path, bridge switching the service on the failed service path to the protection path, and modifying the service priority of the protection path to be the service priority of the failed service path; the method further comprising: if there are a plurality of service paths of which the service priorities are lower than that of the failed service path and meanwhile are the lowest, then selecting therefrom a service path which is a non-protection path as the protection path of the failed service path; if plurality of service paths of which the service priorities are lower than that of the failed service path and are also the lowest service priority, are all protection paths already, then selecting a protection path having the lowest fixed priority therefrom as the protection path of the failed service path. A. setting priorities of services carried on service paths participating in linear protection of the optical network as service priorities; and B. selecting, from the service paths participating in the linear protection, a service path of which the service priority is lower than that of the failed service path as a protection path, and bridge switching the service on the failed service path to the protection path; characterized in that: the method further comprising the following step before step B: configuring fixed priorities for the service paths participating in the linear protection of the optical network and setting the service priorities of the service paths to be equal to the fixed priorities; wherein the step B comprises: selecting, from the service paths participating in the linear protection, a service path, of which the service priority is lower than that of the failed service path and meanwhile is the lowest, as the protection path, bridge switching the service on the failed service path to the protection path, and modifying the service priority of the protection path to be the service priority of the failed service path; the method further comprising: if there are a plurality of service paths of which the service priorities are lower than that of the failed service path and meanwhile are the lowest, then selecting therefrom a service path which is a non-protection path as the protection path of the failed service path; if plurality of service paths of which the service priorities are lower than that of the failed service path and are also the lowest service priority, are all protection paths already, then selecting a protection path having the lowest fixed priority therefrom as the protection path of the failed service path. configuring fixed priorities for the service paths participating in the linear protection of the optical network and setting the service priorities of the service paths to be equal to the fixed priorities; wherein the step B comprises: selecting, from the service paths participating in the linear protection, a service path, of which the service priority is lower than that of the failed service path and meanwhile is the lowest, as the protection path, bridge switching the service on the failed service path to the protection path, and modifying the service priority of the protection path to be the service priority of the failed service path; the method further comprising: if there are a plurality of service paths of which the service priorities are lower than that of the failed service path and meanwhile are the lowest, then selecting therefrom a service path which is a non-protection path as the protection path of the failed service path; if plurality of service paths of which the service priorities are lower than that of the failed service path and are also the lowest service priority, are all protection paths already, then selecting a protection path having the lowest fixed priority therefrom as the protection path of the failed service path. if there are a plurality of service paths of which the service priorities are lower than that of the failed service path and meanwhile are the lowest, then selecting therefrom a service path which is a non-protection path as the protection path of the failed service path; if plurality of service paths of which the service priorities are lower than that of the failed service path and are also the lowest service priority, are all protection paths already, then selecting a protection path having the lowest fixed priority therefrom as the protection path of the failed service path.