In the method, a detection agent apparatus receives location information of a monitoring point on a service path that is sent by a detection control apparatus, where the detection agent apparatus is located in the NFV system; the detection agent apparatus obtains fault locating information from the monitoring point based on the location information of the monitoring point, where the fault locating information is information obtained by the monitoring point according to a filter criterion, and the fault locating information includes the location information of the monitoring point; and the detection agent apparatus sends the fault locating information to the detection control apparatus, where the detection control apparatus may determine a faulty monitoring point based on the fault locating information and a service model corresponding to the service path.