Abstract: The present invention is in the field of sports equipment, more specifically, relating to a trampoline frame connection structure. The trampoline frame has a main pipe and a support pipe. The main pipe has a straight line weld seam. The support pipe supports the main pipe. The main pipe junction with the support pipe has a concave connection. The main tube weld seam is on the bottom facing the concave portion. This practical new design features an improved welding configuration that has a low budget and high-efficiency connection. The weld seam on the bottom decreases shock to the weld seam and also prevents interference between the connecting hole on the main pipe and weld seam. Finally, this invention uses a weld seam strengthening plate device.