The four-in-one pump-suction voice gas detector(hereinafter referred to as the detector) is a safe device that can be used continuously to detect the concentration of leaking gas. The detector can effectively predict the concentration of dangerous gas and alarm to ensure that the life safety of the staff is not threatened and the production equipment is not lost, which is widely used in petroleum, chemical, environmental protection, metallurgy, refining, gas, biochemical medicine, agriculture, fire protection, archaeology and other industries and places that require safe monitoring of toxic, hazardous and explosion-proof.