Abstract: The present invention relates to a tube assembly for controlling the length of a syringe needle. The tube assembly comprises: a coupling body wherein one end is coupled with a needle assembly having a fixing member coupled to the upper end of a syringe cylinder and a syringe needle coupled to the fixing member; and a control tube formed to enable control of exposure length of the syringe needle by being movably coupled to the coupling body along a longitudinal direction of the syringe needle. The coupling body comprises: a coupling part formed on a lower side thereof to be inserted into and coupled to the fixing member, and a through-hole formed therein in order for the syringe needle to penetrate the through-hole and to protrude out of the front end.