The present invention discloses a supersonic inlet with synchronous adjustment of capture area and throat area, wherein the throat area may be adjusted by providing a movable throat section, while the capture area may be adjusted by providing a movable cowl section at the front end of the cowl lip, thereby realizing the effect that the capture area and the throat area of the inlet may be adjusted in synchronization. Meanwhile, the present invention also provides a control method and a design method of the above-mentioned inlet. The present invention greatly simplifies the actuation system and control system, significantly reduces the weight of the accessory system, and enables the performance of the inlet within a wide envelope range to be maintained in an excellent state.