A stretch exercise system includes a waist harness, an upper limb extension unit having a right and a left upper limb elastic straps which are set symmetrically on the waist harness, a wrist loop, a lower limb extension unit having a right and a left lower limb elastic strap units which are set symmetrically on the waist harness, two Achilles tendon retro-stretch angle units connecting with the right and the left lower limb elastic strap units respectively, and two sole fastening units set thereon respectively to hold feet of a user. When the system is operated, a static balance is reached with a force applied on the upper limb extension unit and a force applied on the Achilles tendon retro-stretch angle units by the user.