Service data transmission method and device

The invention relates to the field of communication technologies, in particular to a service data transmission method and device. The service data transmission method and device are used for solving the problems that service transmission reliability is low and the caching cost of a receiving end is high when multiple paths of service data having relative delay demands are transmitted in an OTN. According to the method, firstly, each path of received service data is written into a cache space corresponding to the path of service data; next, service data are taken out from cache spaces corresponding to all paths of service data having the relative delay demands and are combined; finally, a path of service data after combination is obtained and sent. By the adoption of the service data transmission method and device, the service data having the relative relay demands can be bound into one path of service data to be sent, therefore, relative delay among various paths of service data can be absorbed without increasing a large-capacity cache at the receiving end, the caching cost of the receiving cost is saved, and the transmission reliability is improved.