The invention relates to a clamping arm-type gas exhausting device. The clamping arm-type gas exhausting device comprises guide rails arranged below a material bag clamp holder, and the two guide rails are separated to be arranged in a conical shape. A gas exhausting clamping assembly is movably installed between the two guide rails. The gas exhausting clamping assembly comprises clamping arms which are vertically installed on the guide rails in a sliding mode and are symmetrically arranged left and right. Each clamping arm is in a bent angle shape, and sliding wheels which are installed on the corresponding guide rails in a sliding mode are arranged at the bent angle positions. The upper ends and lower ends of the clamping arms tilt towards the positions between the two guide rails. Clamping bars are installed at the upper ends of the clamping arms. A lifting assembly is connected between the lower ends of the two clamping arms. The lifting assembly comprises a guide block used for being inserted into the lower ends of the two clamping arms, and a lifting rod which is fixedly connected under the guide block. The lower end of the lifting rod is connected with a lifting driver. The clamping arm-type gas exhausting device is compact and reasonable in structure, the two bent angle-shaped clamping arms are combined with the conical guide rails, gas in packaging bags can be exhausted conveniently, the effect is obvious, gas exhausting time is saved, packaging quality of the packaging bags is greatly improved, and the working efficiency is also improved.