The invention provides a dry-type decoking method of an oil shale gas retort with an screw conveying structure, which is characterized in that the semicoke passes through a discharging tube and enters a feed delivery pipe of a primary feed delivery equipment or the feed delivery pipes of a first and second feed delivery equipment, wherein the semicoke is discharged from an ash discharge hole at the bottom part of the oil shale retort furnace with the temperature of 300-550 DEG C and the particle size greater than 0-75mm; the discharging tube is connected with the bottom part of the oil shale gas retort in a sealed manner; the discharge hole maintains a feed level of 2-3m; the inclined angle between the feed delivery pipe and a horizontal plane is 0-40 degrees; the feed level of the discharging tube is controlled by the feeding speed of a screw rod; the temperature of the semicoke is lowered to 50-100 DEG C by a water circulation refrigerating system; an inflation opening provided on the feed delivery pipe is filled with nitrogen of 0.5 MPa for sealing; and a motor drives the screw rod arranged in the feed delivery pipe to rotate so as to feed the semicoke to the furnace. The oil shale semicoke obtained by the invention has no external moisture; the heating quantity can reach 800-1600 kcal/kg; and the invention has the advantages of short flow, even feed delivery, no blocking, little vibration, favorable sealing effect, no leakage of gas, environmental protection in use and low cost and the like.