The invention discloses a data emission detection method and system and a mobile terminal, and belongs to the mobile terminal technical field; the method comprises the following steps: S1, the mobile terminal sends to-be-sent data corresponding to a present data emission process to a system buffer memory of the mobile terminal, thus finishing emission preparation operations aiming at the present data emission process; S2, the mobile terminal carries out uplink channel coding for the to-be-sent data, verifies the to-be-coded to-be-sent data, and turns to step 3 if verification fails; S3, the mobile terminal actively stops the present data emission process and quits; the system comprises an emission preparation unit, a coding unit, an emission unit, a verification unit and a control unit. The beneficial effects are that the method and system can prevent useless data retransmission operations caused by emitting ineffective data, thus reducing data emission delay, and improving data emission efficiency.