The invention relates to a method for degassing liquefied petroleum gas waste alkaline residues, which aims at solving the problems of environment pollution and waste of waste gas in the prior art. According to the method for degassing liquefied petroleum gas waste alkaline residues, firstly liquefied petroleum gas and alkali liquid contact in an alkali washing tower to obtain an effluence (1), then the effluence (1) enters a settling tank for settling separation, gas phases are emitted from the top of the settling tank, alkali liquid on the bottom part of the settling tank containing liquid hydrocarbons enters an alkaline residue degassing tank for degassing, hydrocarbon components obtained from the top of the alkaline residue degassing tank enter a low pressure gas pipeline network, and alkaline residues obtained from the bottom part of the alkaline residue tank are conveyed to a post treatment device, wherein the operation conditions of the alkaline residue degassing tank are that the pressure measured by a pressure gauge is from -0.08 MPa to normal pressure and the temperature is larger than zero DEG C and reaches 95 DEG C. Based on the method, the problems are solved, and the method can be used for degassing of liquefied petroleum residues.