The utility model provides a semitrailer rod structure, the upper end of pull rod and the dock Panel fixed connection on the semitrailer, the lower extreme of pull rod and the otic placode fixed connection on the semitrailer, the quantity of pull rod is two, just parallel arrangement is gone up at same vertical face to two pull rods, add the fixed joint of break -over dock Panel thickness direction with pull rod corresponding position on dock Panel, fixed joint and the coaxial setting of pull rod, fixed joint's both sides all with dock Panel fixed connection, add lock nut, the upper end of pull rod is provided with the external screw thread, the pull rod upper end forms the locking cooperation with lock nut after passing fixed joint. Can effectual reduction dock Panel the flexural of bottom institute square, improve the equivalent stiffness of dock Panel structure, especially can effectual reduction start -up, the braking process is to dock Panel's impact. Dock Panel is direct to be contacted with the pull rod, can the effectual vehicle operation of reduction vibrations strike the tired of pull rod, and the cracked risk of greatly reduced pull rod, the stability of car operation is put in order in the improvement.