The invention provides a parallel data-to-serial data transmission method comprising the steps of extracting preset parameter information of each parallel channel, the parameter information being used for separating different parallel channels and data transmission time of the different parallel channels; making data packets for transmission out of collection data of each parallel channel and the preset parameter information corresponding to each parallel channel; performing serial transmission on the data packets of the parallel channels according to an arrival order. Through packaging transmission of data and parameter information, the method prevents data delay and data disorder, and improves the data transmission efficiency and transmission accuracy while guaranteeing the consistency of clocks and data.