A arm external fixing brace (10), characterized by a thickness (H) of an edge of a mesh panel (12) thereof being greater than a thickness (B) of a central location. Selectively, raw materials of the mesh panel (12) being, according to weight: 60-78% PCL； 20-38% EVA； 2-20% inorganic filler； a thickness of an edge of a large ventilation hole of the mesh panel (12) being less than a thickness between the centers of two adjacent large ventilation holes； multiple fastening base plates (300) being pre-embedded at adjacent horizontal edge locations of the mesh panel (12)； two wings of a fastening base plate (300) being provided with side holes (305), two sides of a middle part of a fastening base plate (300) being provided with grooves (302, 303) having symmetrical structures, the middle part of a fastening base plate (300) being provided with a middle hole (304), and a non-return surface (301) being provided at two sides of a circumference of the middle hole (304) inside the grooves (302, 303)； two sides of a thumb hole (15) of the mesh panel (12) being tapered surfaces having symmetrical structures. The arm external fixing brace has few components, but simultaneously can prevent adhesion during a molding process so as to facilitate removal from a mold, make clinical operation convenient, and be comfortable to wear, metrics which were previously in conflict with one another.L'invention concerne une attelle externe de fixation de bras (10), caractérisée par une épaisseur (H) d'un bord d'un panneau en treillis (12) de celle-ci étant supérieure à une épaisseur (B) d'un emplacement central. De manière sélective, les matières premières du panneau en treillis (12) sont, selon le poids : 60-78 % de PCL ； 20-38 % d'EVA ； 2-20 % de charge inorganique ； une épaisseur d'un bord d'un grand trou de ventilation du panneau en treillis (12) étant inférieure à une épaisseur entre les centres de deux grands trous de ventilation adjacents ； de multiples plaques de base de fixation (300) éta
