The present application provides a method, a device, a transmitter, and a receiver for detecting syncwords. After inserting syncwords in a data frame to be transmitted, a transmitter transmits the data frame to be transmitted inserted with a preset number of syncwords to a receiver. Because the bit-length of information in the data frame to be transmitted inserted with the preset number of syncwords is a specified multiple of the length of the syncwords, and the symbol components of the preset number of the inserted syncwords are different, or the symbol components are the same but the orders of the symbols are different, the receiver correlates each syncword of the preset number of syncwords with the data frame to be transmitted inserted with the preset number of syncwords after receiving the data frame to be transmitted.