Telescopic single-tube telescope capable of fast focusing

The utility model relates to a telescopic single-tube telescope capable of fast focusing, which comprises a first lens body, a second lens body arranged in the first lens body and a third lens body arranged in the second lens body, and is characterized in that one end, far away from the second lens body, of the first lens body is in threaded connection with a second adjusting tube; the end, away from the second mirror body, of the third mirror body is in threaded connection with a first adjusting cylinder, fixing grooves are formed in the outer wall of the second mirror body and the outer wall of the third mirror body, limiting holes are formed in the outer walls, located on the tops, of the first mirror body and the second mirror body, fixing rods are arranged in the fixing grooves, and separating mechanisms are arranged in the limiting holes. After the fixing rod and the limiting hole are separated through the separating mechanism, the single-tube telescope can be contracted to achieve the effect of being c