An embodiment of the invention discloses a network communication function abnormity processing method. The method comprises the following steps that a modem detects that MT/MO calling is failed; the modem determines whether an abnormal condition that MT/MO callings with a set frequency are failed is generated in set time; if a determination result is positive, the modem acquires a first protocol stack which is used by the modem currently; the modem closes the first protocol stack and selects a second protocol stack from a plurality of protocol stacks supported by the modem, except for the first protocol stack; the modem starts the second protocol stack and uses the second protocol stack to carry out network registration; if the network registration is successful, the modem records current position information. The embodiment of the invention also discloses the modem and a mobile terminal. By using the method, the modem and the mobile terminal of the invention, the abnormity of the network communication function can be rapidly detected and recovered.