The present invention relates to a protective case for preventing damage to a mobile terminal, comprising: an actuator (12) comprising a piezoelectric vibrating screen (17) formed by attaching a piezoelectric element layer (20) to at least one side of a substrate (18), at least one or more weight pieces (22) which are fixedly attached to the piezoelectric element layer (20) and increase the vibration force, and a bracket (24) provided so that both ends of the substrate (18) are fixedly attached thereto; an auxiliary battery (10) which supplies power to the actuator (12) and is used for charging in the case where a battery of a mobile terminal (4) is discharged or consumed; and a Bluetooth receiving module (30) for receiving a signal transmitted from a Bluetooth transmitting module (28) of the mobile terminal (4). As the actuator (12), which provides real-time vibration feedback, is installed in the inner side of the protective case (2)(2a) which is worn for preventing damage to the mobile terminal (4), the protective case has an effect of giving a user simultaneous sensory stimulation by providing the user with a haptic signal corresponding to an image and sound outputted from the mobile terminal (4) as a rapid vibration response. In addition, the protective case can transfer various vibration patterns including strong vibration and micro vibration as the vibration amount of the actuator (12) is adjusted according to the magnitude of vibration, or a vibration motor (14) is controlled so as to provide vibration feedback at low frequency, and thus, the protective case has an effect of giving the user a sense of realism.