The invention discloses a simple network management protocol (SNMP)-based reliable data transmission method. In the method, two variable object identities (OIDs), namely a data transmission value domain and a control domain, are added into a management information base (MIB) expanded for data transmission, and a control domain OID node comprises two OIDs, namely, the OIDs of a data type variable and a system status variable, wherein the transmitted data type is specified according to the data type, a data value is transferred by a value domain, the reliability of every transmission is guaranteed by a system status, and once a management station receives a data transmission request of an agent or the agent receives the data transmission request of the management station, values of the system status of both the management station and the agent are changed into 1, at the time, any other data transmission requests of the agent or the management station are ignored till the data transmission is finished, and the value of the system status is changed into 0 again. Therefore, each data transmission can be fully and correctly finished, and the data is guaranteed to be transmitted orderly,correctly and reliably.