Some unknown residual pile foundations are encountered during the construction of launching shaft and receiving shaft of pipejacking tunnel in urban area. The location and scope of residual pile foundation in the construction area are not clear. As a result, it is necessary to find out whether there is any residual pile foundation in the tunnel area before carrying out construction. Only the geophysical method can be adopted for there is no condition for extensive drilling exploration. The method of residual pile foundation detecting by ground penetrating radar and magnetic method, which can meet the detection requirements, are selected. According to the detection results, the drilling verification in abnormal area is carried out and the countermeasures are taken to guarantee safe construction of pipejacking tunnel.