The automatic pick of the first arrivl time has been one of the basic and important problems in seismic exploration. Based on some simple assumptions, previous researchers have already put forward several computerized algorithms for automatic pick of first arrival time; neverthless, the pick precision is always affected by noise and waveform variation. This paper advances a technique for picking the first arrival time, composed jointly of an improved dip angle scanning correlation algorithm and an improved energy ratio method. After conductig noise suppression for seismic channel by means of scanning correlation algorithm, this technique employs the energy ratio method to determine rough first arrival time of the possibly existing effective wave, then uses the dip angle scanning correlation algorithm to verify the existence of effective wave, uses the peak value method and the inflection-point correction method to evaluate the precise first arrival time and, finally, uses empirical criteria for hand pick to examine the reliability of the first arrival and correct the interchange time.The algorithm put forward in this paper has been realized on Z-181 microcomputer, with fairly good results obtained in the automatized interpretation of refracted wave exploration for protection of cultural relics in Lian-yungang City, Jiangsu Province.