Abstract: In this paper, using matched filtering technology, the missing seismic phases of the Douhe earthquake swarm on september10 to 12 in 2016 in Tangshan region are detected. In the detection, the largest earthquake in the swarm is taken as the template of the existing earthquake catalog produced by Hebei seismic network. The continuous waveforms are cross-correlated scanned to determine the occurrence time of the missing earthquake; The magnitude of missing earthquakes is estimated by using S wave amplitude ratio method; Location of observed earthquakes is determined by simple seismic location method. The results show that a total of twenty two missed earthquakes were detected which improve the earthquake catalog.