The invention provides a linear protection switching method, a PE (Provider Edge) device and a system. The linear protection switching method comprises the steps of acquiring a first state and a first switching decision of a near-end PE device and sending the first state of the near-end PE device to a far-end PE device when the near-end PE device receives local end non-fault input; acquiring a second state and a second switching decision of the far-end PE device and sending the acquired second state of the far-end PE device to the near-end PE device after the far-end PE device receives the first state of the near-end PE device; determining whether link switching is carried out or not by the far-end PE device according to the acquired second state and the second switching decision; acquiring a third state and a third switching decision of near-end PE device after the near-end PE device receives the second state of the far-end PE device; and determining whether link switching is carried out by the near-end PE device or not according to the acquired first switching decision and the third switching decision. The technical scheme provided by the invention enhances the controllability and the manageability of a network, and effectively avoids a problem of timeliness and a problem service interruption, which lasts for 5s at most, in the process of operating the network.