The inventive device for thermomechanically joining pipes (1, 2) comprises a joining working organ which encompasses the end of the pipes (1, 2) to be joined and is made of a shape memory material, wherein the joining working organ is in the form of a bellows (3) with a cooling-and-heating unit (7) which is coupled to an energy carrier source and is designed in the form of two pipe coils arrangedoutside the bellows (3) between the corrugations thereof, the bellows (3) and the pipe coils are enclosed in a hermetical dismountable cylindrical jacket which consists of two parts (5, 6), a thermalprotective shell is attached to the inner surface of the jacket and flanges (23) with a rubber pad (24) are made on the end faces thereof, said flanges are conjugated with the pipe (1, 2) ends to be joined, the pipe coils are secured on the corresponding parts (5, 6) of the jacket and elastic sealing rings (10) are placed on the surface of the bellows (3) corrugations contacting the pipe (1, 2) ends to be joined.