The invention discloses a manufacturing method for a post-cast awning on the side face of a prefabricated reinforced concrete frame beam. The manufacturing method comprises the steps that firstly, awning load-bearing bar holes are formed in the side face of a die of the prefabricated reinforced concrete frame beam, the interval is 300, and the upper part and the lower part are each provided with arow of the awning load-bearing bar holes; secondly, awning load-bearing bars are produced; thirdly, when the prefabricated reinforced concrete frame beam is manufactured and bars are bound, bar mechanical sleeves are embedded on the side face of the die according to the hole-formed positions of the die, and the embedding segments of the awning load-bearing bars are connected with the embedded barmechanical sleeves; and the exposed ends of the embedded bar mechanical sleeves are sealed, and exposed holes are blocked through rubber plugs; fifthly, after a reinforced concrete frame beam is bound completely, concrete is poured in a factory; sixthly, the prefabricated members are transported to a site; seventhly, after the prefabricated members are hoisted completely on site, awning formworkerecting is carried out; eighthly, the awning load-bearing bars and the embedded bar mechanical sleeves are connected and fixed; ninthly, load-bearing longitudinal bars, distributed reinforced bars and horizontal distributed bars are bound; and tenthly, concrete is poured. The invention further provides the post-cast awning and the prefabricated reinforced concrete frame beam.