The invention relates to a dome brasses installing system. The dome brasses installing system comprises foundation seats, first fixing assemblies, brasses and second fixing assemblies; the foundation seats are connected with steel frame bases through the first fixing assemblies; the brasses are connected with the foundation seats through the second fixing assemblies; the first fixing assemblies and the second fixing assemblies both comprise bolts, soft spacers and spring spacers; and the bolts penetrate through the soft spacers and the spring spacers. According to the dome brasses installing system, the installation of the brasses is more convenient; a fast installing effect is achieved; meanwhile, the degree of fixation and fastness is improved and water leakage is avoided; and besides, gluing processing is not needed due to the fact that the similar superposition principle as traditional tiles is adopted to form a self-structure water drainage effect; and the adjacent brasses are covered through folded edge increasing and edge covering treatment, so as to prevent human eyes from seeing the fixing bolts directly and prevent the brasses from flashing.