The invention discloses a treatment system for polymethoxy dimethyl ether salt-containing wastewater. The treatment system comprises an I-effect evaporating heater, an I-effect evaporating separationchamber, an II-effect evaporating heater and an II-effect evaporating separation chamber, wherein an I-effect separating pipe is arranged between a discharging opening in the top end of the I-effect evaporating heater and the side wall of the I-effect evaporating separation chamber in a communicating manner; an I-effect circulating pipe is arranged between the bottom of the I-effect evaporating separation chamber and the bottom end of the I-effect evaporating heater in a communicating manner; a wastewater inlet pipe is communicated with the side wall of the I-effect circulating pipe; an II-effect separating pipe is arranged between a discharging opening in the top end of the II-effect evaporating heater and the side wall of the II-effect evaporating separation chamber in a communicating manner. The processing system disclosed by the invention has the advantages that sodium formate is recovered while the wastewater is treated, so that environmental protection, emission reduction and comprehensive utilization of resources are realized. The chemical oxygen demand (COD) of desalted condensed wastewater of the system is reduced to 2000mg/L or below, and the salt content of the desaltedcondensed wastewater is reduced to 1000PPM or below.