The invention relates to a novel 45-degree wing-angle G-section switch cabinet body which is characterized in that a main body frame adopts a square frame-type structure comprising four stand columns and eight cross beams arranged in an up-down manner; the stand columns are made of reinforced open sections; the cross beams are made of G-sections with 45-degree wing angles; the openings of the sections are inward; the joints of the three parts are subjected to frame mounting by sheet metal tee joint parts; the stand columns are fixed with the cross beams through positioning and fixation of the sheet metal tee joint parts and the positioning holes and indenting counter bores of the stand columns as well as the sheet metal tee joint parts and the positioning holes and indenting counter bores of the cross beams, and positioning of the bayonets of the stand columns and the cross beams; functional modulus square holes and round holes are uniformly formed in the stand columns and the cross beams. The cabinet body adopts the modulus reinforced open sections of 20 mm and the G-sections with the 45-degree wing angles, and is relatively compact and relatively high in utilization rate in comparison with a common modulus design of 25 mm; the square holes and the round holes with the diameters of 5.3 mm are uniformly formed in the central axes of the short edge sides of the sections at an interval of 1/2 modulus.