The present invention relates to a gas combustor, which comprises a housing in which a base seat is installed, an engagement pipe at the front of the base seat is connected to a flame device exposed at the front of the housing, wherein the rear portion of the base seat is pivoted with a swing sheet, the inner surface thereof is adjacent to a gas intake control valve fastened in the base seat, and a convey pipe is connected between the gas intake control valve and a pivotal connection device installed at the rear of the housing; and a safety mechanism, installed at the bottom of the housing and including a latch button, a connection rod and a control button; through pressing the latch button, one end of the connection rod is raised, the latch end at the other end of the connection rod is inwardly retracted for releasing the locking state of the control button, so the control button is enabled to be pressed, and the extrusion part extrudes the swing sheet, and the gas intake control valve is formed to an opening state, so the fuel is able to pass through the interior of the base seat for being ejected by the flame device.