Provided are a flexible electronic device and an operation method thereof. The electronic device may include a housing, a flexible display including a first portion and a second portion, a first sensor and a second sensor, a third sensor, at least one processor, and a memory. The processor may monitor whether or not the flexible display switches from a folded state to an unfolded state using the third sensor. The processor may at least partially activate the first sensor and the second sensor, based on the case where the flexible display switches from the folded state to the unfolded state. The processor may measure relative position and/or angle of the first portion and the second portion in the flexible display using the first sensor and the second sensor. In addition, various other embodiments may be provided.