The invention relates to a spring testing machine. Therefore, a problem that a spring is easy to separate to injury someone when a spring testing machine carries out pulling and pressing tests on a spring in the prior art can be solved. According to the spring testing machine, a protection structure is arranged on a rack. During a process of carrying out a stretching test or compression on a spring, when a tested spring disengages from a testing machine due to eccentricity, the motion of the disengaged spring in a horizontal direction can be stopped by the protection mechanism and thus the spring can not pops up from the side of the rack to injury the operator, so that the operation security of the spring testing machine is improved.