The invention provides a call routing method and system of number portability businesses as well as network element equipment. The call routing method comprises the following steps of: receiving a roaming number search request of a first IMSI (International Mobile Subscriber Identity) number assigned by a first network which originally belongs to a terminal with signed number portability businesses; according to pre-stored first mapping information, searching a user number of the terminal corresponding to the first IMSI number of the terminal, and a second IMSI number assigned by a second network which belongs to the terminal at present; verifying the terminal according to the searched second IMSI number of the terminal, and determining call routing information corresponding to the terminal according to pre-stored second mapping information when the verification is successful; and sending a roaming number search response to the first network, wherein the response comprises the determined call routing information corresponding to the terminal and the user number of the terminal. According to the call routing method provided by the invention, in the condition that the terminal is received from the first network which originally belongs to the terminal with the signed number portability businesses as a called call request, the realized technical scheme is provided for the call routing of the terminal.