The routinely picked results of first arrival of air-gun source data is poor, mainly because of its low signal-to-noise ratio (SNR). The anthors introduce the seismic exploration methods to pick the first-arrival and proposes a scheme for picking first-arrival in three stages to reduce the dependence on data’s SNR. Firstly, the noise was depressed. And then, the traditional exploration method was used to calculate the characteristic curve. Finally, the first-arrival was determined by combining the edge-preserving smoothing method. On this basis, according to the characteristics of practical data, the authors design an automatic pick-up process, which is used to pick up the first arrival of practical data. Compared with the traditional method, this method requires less SNR for the data and provides more available materials for subsequent processing and analysis.