The invention provides a network control method and a network control device for a door lock, a server and a PMS (Property Management System). The method comprises the following steps of receiving room reservation request information, and generating corresponding order information according to the room reservation request information; generating a guest room unlocking code corresponding to the order information; storing a corresponding relationship between a guest room identifier corresponding to the order information and the guest room unlocking code; transmitting the guest room unlocking code to the door lock corresponding to the guest room identifier. According to the network control method and the network control device for the door lock, the server and the PMS provided by the invention, the guest room unlocking code is generated according to the order information of room reservation by a user, and the corresponding relationship between the guest room identifier and the guest room unlocking code is stored, so that network control of the door lock is realized; in addition, the user can open a corresponding guest room by using the guest room unlocking code as long as the guest room unlocking code is informed to the user, so that manual intervention in the control process of the door lock is reduced, and the control efficiency of the door lock is improved. Besides, the guest room unlocking code has no real carrier, so that the possibility that the guest room unlocking code is lost is reduced, and the control safety of the door lock is improved.