A network quality determining method includes, when experience quality represented by a customer experience index of a target user within a first time period is lower than experience quality represented by a customer experience index threshold, determining, using a first parameter value that is of a network key performance indicator (KPI) parameter of the target user within a second time period and that is collected by a collection device in a carrier network, a second parameter value of the network KPI parameter of the target user within the second time period in a home network, and when network quality represented by the second parameter value of the network KPI parameter is lower than network quality represented by a first threshold corresponding to the network KPI parameter in the home network, determining that quality of the home network is poor.