A safety seat is provided, including a seat base and a seat back. The seat back includes a framework adjustable in shape and a covering part covering the framework and made of flexible material. A surface of the covering part is provided with multiple sensors for obtaining back position information of a person sitting on the safety seat. The safety seat further includes a data processing device and a driving structure. The data processing device is for receiving the back position information, determine a shape of a back surface of the person and send a covering part adjustment signal. The driving structure is for adjusting a shape of the framework according to the covering part adjustment signal and changing a shape of the surface of the covering part by changing the shape of the framework so as to match the shape of the back surface of the person.