The child safety restraint system comprises a seat main part which is a segmented inflatable airbag seat including a cushion-backrest integrated part in the middle and armrest-head guard integrated parts on two sides, wherein the cushion-backrest integrated part is formed by wrapping a cushion-backrest integrated airbag with a cushion-backrest integrated fabric, and the armrest-head guard integrated parts are formed by wrapping armrest-head guard integrated airbags with armrest-head guard integrated fabrics; head guard segments of the armrest-head guard integrated parts are able to shield against glass fragments splashed into a car when window glass is hit laterally; the cushion-backrest integrated part and the armrest-head guard integrated parts are provided with inflation-deflation valves; and car safety-belt fasteners are arranged between armrest segments and the head guard segments of the armrest-head guard integrated parts. A safety seat comprises a shoulder-type elliptical annular front protection body.