The invention discloses a mobile phone for the aged and a service system of the mobile phone. The mobile phone runs correspondingly according to a main battery potential test result from a power detection unit. For example, if the power detection unit detects that the current potential is below a first potential, then commands a communication module to send ID of the mobile phone and residual power percentage information to a remote service center; if the power detection unit detects that the current potential is blow a second potential, a main control module controls the communication module to limit working hour and forbid part of functions; if the power detection unit detects that the current potential is below a third potential, a backup battery is started to replace the main battery to supply power for different modules, the ID of the mobile and SOS signals are sent to the remote service center. Standby time of the mobile phone can be prolonged, power information of the mobile phone can be sent to the remote service center in time, and family members can know traces of the aged and power conditions of the mobile phone through the remote service center.