Disclosed in the present application are a transmission rate control method and apparatus, a sending device and a receiving device. The transmission rate control method is applied to a DCN, and comprises: a sending point receiving a first CNP sent by the receiving point, the first CNP comprising rate information, the rate information indicating a receiving rate of the receiving point receiving data packets included in the data flow; determining the receiving rate according to the rate information; determining an emptying rate according to the receiving rate; updating the sending rate of the data flow to be the emptying rate. In technical solutions of the present application, the sending point adjusts the sending rate of the data flow according to the rate information concerning the receiving point, and enables an accurate adjustment of the sending rate of the data flow, thereby eliminating queue congestion of a transmission point, improving the transmission performance of the data flow.