Abrasive water jet cutting technology can meet the requirements of emergency repair for oil and gas storage and transportation facilities. Through cutting experiments which were carried out on pipeline steel by portable abrasive water jet cutting system to research the cutting characteristic, the law for impacts of pressure, standoff distance and traverse rate on cutting depth was obtained, and then a cutting depth prediction model was put forward. The results show that the cutting depth is proportional to the pressure and inversely proportional to the standoff distance and the traverse rate. The maximum error of prediction result of the cutting depth by the cutting depth model is 1504%, the minimum error is 087%, and the average error is 598%, which shows that the cutting depth model can effectively guide the cutting process establishment in a certain parameter range.