The invention relates to the technical field of smart phones, and discloses a smart phone SIM card slot device convenient for card taking. The device comprises a rack, a baffle is slidably connected to the interior of the rack, a button is slidably connected to the top of the baffle, a buffer spring is fixedly connected to the bottom of the button, and an air valve is slidably connected to the inner wall of an air cavity. And a tension spring is fixedly connected into the containing frame, a magnetic plate is fixedly connected to the side, close to the gear, of the tension spring, and a transmission wheel is in transmission connection with the top of the gear. According to the SIM card slot device convenient for taking out the card for the smart phone, a button is pressed, so that an air hole is communicated, air pushes an air bag to expand, the air bag drives a sliding plate to slide, the sliding plate drives a supporting spring to move, the supporting spring drives a clamping block to move, a guide rod rises under the action of a reset spring, and the guide rod is matched with a baffle for use; therefore, the effects of automatic ejection without an ejector pin and convenience inuse are achieved.