A checking and focusing device for an telescope eyepiece includes an eyepiece barrel formed of an inner tube and an outer tube. The outer tube has at one end a clamping portion formed with multiple resilient segments in a radial shape. A locking ring is threaded onto the clamping portion so that rotating the locking ring can gradually constrict the resilient segments to clamp the eyepiece tightly without biasing its axis. A production process for the chucking and focusing device for an telescope eyepiece includes two steps. One step is to machine multiple lengthwise grooves in an inner surface of a metal tube, the thickness of the grooves being the same as the depth of the resilient segments. The tube is then machined until the grooves are exposed, forming a single elastic strip between every two grooves, forming the clamping portion of the tube.