The present disclosure relates to a life-saving apparatus and system for fire hazard in buildings. The life-saving system includes a main gas supply pipe and a main gas discharge pipe, the main gas supply pipe is provided with auxiliary gas supply pipes which includes a gas supply port located outside the main gas supply pipe and a gas inlet port located inside the main gas supply pipe, with the position of the gas supply port of the auxiliary gas supply pipe being higher than that of the gas inlet port; the main gas discharge pipe includes auxiliary gas discharge pipes which includes a gas discharge port located outside the main gas discharge pipe and a gas outlet port located inside the main gas discharge pipe, with the position of the gas discharge port of the auxiliary gas discharge pipe being lower than that of the gas outlet port.