An electronic device with extendable strap and different communication modes depending on the state of the strap comprises a shell, at least one rotating mechanism, a strap, a sensor, and a processor. The shell defines at least one first receiving cavity, the rotating mechanism is received in the first receiving cavity. One end of the strap is wound on the at least one rotating mechanism. The rotating mechanism is able to rotate and store spring force under a driving of the strap. The sensor communicates with the processor to determine the state of the strap according to a rotation direction of the rotating mechanism and thus determine whether the strap is retracted to allow touch screen input by a user, or extended to switch to voice communication with the user.