A trampoline support frame comprises a plurality of transversal branch pipes (1) and a plurality of longitudinal branch pipes (2). The transversal branch pipes (1) are connected to each other to form an annular fiame. Each of the longitudinal branch pipes (2) is provided with a fitting portion (21) and two reinforcing portions (22) integrally extended from the fitting portion (21) to corresponding two side surfaces of the transversal branch pipe (1) and then fixed to the transversal branch pipe (1) by welding, respectively. In this case, the two reinforcing portions (22) of each of the longitudinal branch pipes (2) are extended from and integrally formed with the fitting portion (21), such that each of the transversal branch pipes (1) may be fixed to the two reinforcing portions (22) by welding directly after the transversal branch pipe (1) is placed between the two reinforcing portions (22) without precision alignment, whereby the manufacturing process for the trampoline support frame is simplified, and manufacturing energy consumption is reduced so as to meet requirements for environment protection. Moreover, assembling strength between two opposite outer side surfaces of each of the transversal branch pipes (1) and each of the longitudinal branch pipes (2) is strengthened by means of the two reinforcing portions (22).