The large delay characteristic in the flotation process brings difficulties to the optimal operation of the flotation process. It is of great significance to estimate the lag time of the interaction between the sub-processes in the flotation process and realize the timing alignment of the flotation process for timely adjusting the operation scheme and ensuring the stable operation of the subsequent process. For this reason, this paper takes a gold processing plant in Shandong Province as the background, innovatively uses flow as the research object of flotation time sequence alignment. Based on the flow balance relationship of the whole process and the lag time between subprocesses as the alignment parameter, a timing alignment model based on flow balance is established. By optimizing the time parameters in the model, the timing alignment problem is converted into the flow deviation minimization problem. The differential evolution algorithm is used to optimize the solution and the estimated latency between subprocesses is obtained. The optimization results are in line with the actual situation in the field and the proposed method realizes the timing alignment of the flotation process.