The paper first introduces in detail the combination method with the Brusa model to integrate several regional time series to derive a unified global time series. Then an example from CMONOC （Crustal Movement Observation Network of China） is taken to test if the combination method is feasible. The precision of the integrated time series with the combination method is below 2mm （North） , 3mm （East） , which is the same as the resuhs from the direct integration of the time series. The precision of the baseline is below 6mm; which proves that the combination method can be used to integrate several regional time series to derive a unified global time series.