Arm stretching trainer for physical training

The invention relates to a trainer, in particular to an arm stretching trainer for physical training. The invention provides an arm stretching trainer for physical training, which comprises a mounting seat, a mounting column, a seat, two mounting racks and balancing weights, the mounting column is fixedly mounted on the mounting seat, the seat is slidably mounted on the mounting column, the two mounting racks are slidably mounted on the mounting seat, and the balancing weights are slidably mounted in the two mounting racks respectively. The device further comprises supporting frames and the like, and the supporting frames are fixedly installed on the two installation frames respectively. A trainee pulls a movable rod to move downwards, so that a balancing weight is driven to move upwards along a corresponding mounting frame, the arm strength of the trainee is trained, when the trainee exhausts the force and cannot continue the current weight, a button is pressed, an ejector block ejects an inserting rod to re