The invention discloses a telescopic device for absorbing collision energy of railway vehicle. The telescopic device comprises two mechanisms which function independently and are respectively mounted on the two sides of a vehicle end part, wherein each mechanism comprises an anti-
crawling tooth, a circular energy-absorbing tube, pull rings, cutters, cutter fixing blocks, a mounting base, a cutter base, a guiding cylinder, a double-acting cylinder, a base, bolts, a
torsion spring, a
dowel, locating grooves, a double-acting
electromagnetic valve, a controller and an air
storage tank. The telescopic device is characterized in that when the device is in a non-working state, each double-acting cylinder is in a tension state and pulls the corresponding circular energy-absorbing tube to retract inside the corresponding guiding cylinder; each cutter is pressed on the outer wall of the corresponding circular energy-absorbing tube; before trains collide, each double-acting cylinder pushes the corresponding circular energy-absorbing tube to be ejected out under the action of
high pressure air; each cutter is pressed on the corresponding locating groove of the corresponding circular energy-absorbing tube under the action of the force of the corresponding spring; when each circular energy-absorbing tube retracts towards the interior of the corresponding guiding cylinder under the action of external force, a cutter
cutting type
energy absorbing structure absorbs energy; and if the circular energy-absorbing tubes are not hit after stretching out, each circular energy-absorbing tube is separated from the corresponding cutters through pulling the corresponding cutters or jacking up the cutter heads through the corresponding cylinder under the corresponding cutters, and each double-acting cylinder pulls the corresponding circular energy-absorbing tube into the corresponding guiding cylinder.