The utility model discloses a telescopic operating bench of a two-layer bench of an oil derrick. A guide bench is fixed on the top surface of the two-layer bench, a sliding operating bench is arranged inside the guide bench, a first bearing housing and a second bearing housing are fixed on the two-layer bench, a screw rod passes between the first bearing housing and the second bearing housing, a screw nut is sleeved on the screw rod, a screw nut holder is fixed on the lower surface of the operating bench, a locking device is fixed on the top surface of the two-layer bench, the screw rod passes through the second bearing housing and the locking device, and a handle is fixedly arranged at the end of the screw rod through a key. The utility model has the advantages of simple structure and reasonable configuration, achieves the purpose of not replacing the two-layer bench during the drilling operation using the top driving system or the common travel hoisting system, reduces both drilling cost and labor intensity, and meets the requirement for overall transportation of the operating bench and the two-layer bench.