A reflow oven, said reflow oven being able to operate in air mode and in inert gas mode, and said reflow oven comprising: a heating zone, said heating zone having a plurality of heating zone inlets and a plurality of heating zone outlets, a cooling zone, a blocked exhaust zone, said blocked exhaust zone being located between said heating zone and said cooling zone, and said heating zone, said blocked exhaust zone and said cooling zone being fluid-connected, wherein said blocked exhaust zone has a blocked exhaust zone outlet, a first pipeline, said first pipeline being controllably connected to said blocked exhaust zone outlet and said first pipeline being able to be connected to the ambient environment, a second pipeline and a plurality of outlet branch pipelines (52, 56), said second pipeline being able to be connected to the ambient environment, said plurality of outlet branch pipelines (52, 56) being connected between said plurality of heating zone outlets and said second pipeline, said plurality of outlet branch pipelines (52, 56) being able to connect said plurality of heating zone outlets and said second pipeline, wherein some or all outlet branch pipes (52, 56) of said plurality of outlet branch pipelines (52, 56) controllably connect said plurality of heating zone outlets and said second pipeline, and a third pipeline and a plurality of inlet branch pipelines, said plurality of inlet branch pipelines being connected between said plurality of heating zone inlets and said third pipeline, said plurality of inlet branch pipelines being able to connect said plurality of heating zone inlets and said third pipeline, said third pipeline being controllably connected to said blocked exhaust zone outlet and said third pipeline being controllably connected to the ambient environment so that said plurality of inlet branch pipelines can controllably connect said plurality of heating zone inlets to the ambient environment, and in addition, said plurality of inlet branch pipelines being able to controllably connect said plurality of heating zone inlets and said blocked exhaust zone outlet. a heating zone, said heating zone having a plurality of heating zone inlets and a plurality of heating zone outlets, a cooling zone, a blocked exhaust zone, said blocked exhaust zone being located between said heating zone and said cooling zone, and said heating zone, said blocked exhaust zone and said cooling zone being fluid-connected, wherein said blocked exhaust zone has a blocked exhaust zone outlet, a first pipeline, said first pipeline being controllably connected to said blocked exhaust zone outlet and said first pipeline being able to be connected to the ambient environment, a second pipeline and a plurality of outlet branch pipelines (52, 56), said second pipeline being able to be connected to the ambient environment, said plurality of outlet branch pipelines (52, 56) being connected between said plurality of heating zone outlets and said second pipeline, said plurality of outlet branch pipelines (52, 56) being able to connect said plurality of heating zone outlets and said second pipeline, wherein some or all outlet branch pipes (52, 56) of said plurality of outlet branch pipelines (52, 56) controllably connect said plurality of heating zone outlets and said second pipeline, and a third pipeline and a plurality of inlet branch pipelines, said plurality of inlet branch pipelines being connected between said plurality of heating zone inlets and said third pipeline, said plurality of inlet branch pipelines being able to connect said plurality of heating zone inlets and said third pipeline, said third pipeline being controllably connected to said blocked exhaust zone outlet and said third pipeline being controllably connected to the ambient environment so that said plurality of inlet branch pipelines can controllably connect said plurality of heating zone inlets to the ambient environment, and in addition, said plurality of inlet branch pipelines being able to controllably connect said plurality of heating zone inlets and said blocked exhaust zone outlet.