The invention relates to an MTO/MTP (Methanol to Olefins/Methanol to Propylene) product separating tower bottom solution dewaxing and deoiling method and device. The device comprises an ultrafiltration membrane facility, a biphase cyclone separator and an oil groove. The MTO/MTP product separating tower bottom solution is firstly subjected to ultrafiltration membrane separation, and the ultrafiltrate returns to the product separating tower for cyclic utilization; the ultrafiltration membrane concentrated solution enters the biphase cyclone separator; an oil/emulsified paraffin mixture separated from the top of the biphase cyclone separator enters the oil groove; and the biphase cyclone separator bottom water returns to the ultrafiltration membrane system. The invention also relates to a cleaning scheme of the MTO/MTP product separating tower bottom solution dewaxing and deoiling ultrafiltration membrane device. The method can effectively remove the oil and emulsified paraffin in the product separating tower bottom solution, thereby implementing the continuous stable operation of the device; the membrane flux can be completely recovered by cleaning; and the oil and paraffin in the tower bottom solution are simultaneous recovered, thereby avoiding the waste of resources and reducing the environmental pollution.