The invention discloses a phosphine gas purifier and aims to provide environment-friendly equipment which is high in phosphine gas purification efficiency, safe, reliable and low in operation cost. The phosphine gas purifier comprises a gas inlet, a front-end diffuser, a filtering unit, a clamping slot, a bent frame, a purifying unit, a bracket, a filtering unit cover plate, a main casing, a purifying unit cover plate, a pressing hand wheel, a tail-end diffuser and a gas outlet. The phophine gas purifier is the purifying equipment, industrial waste gas containing phosphine can meet the standard and can be directly exhausted into atmosphere after being purified once by the phophine gas purifier at the normal temperature, the air treatment capacity is 500-50,000 m<3>/h, and the concentration of phosphine in the purified gas is not larger than 0.3 mg/m<3>.