Shaft-like member loading deformation testing device and testing method

Provided is a shaft-like member loading deformation testing device. A vertical clamping seat is vertically arranged on a horizontal support base, and is provided with a clamping tool used for clamping and fixing a shaft-like member to be measured. A screw-nut pairs, loading platform slide rails, and a dial gauge slide rail are parallelly arranged on the horizontal support base at intervals in the center line direction of the shaft-like member to be measured. The bottom of a support framework is fixed on a slide block through nuts of the screw-nut pair, and when a screw rod rotates, the support framework can slide with the slide block on the loading platform slide rails. The support framework is internally provided with a pressure head driven by a jack, wherein the driving pressure head is provided with a pressure sensor, and directly faces the shaft-like member to be measured below; a slidable support seat is installed on the loading platform slide rails through the slide block; a dial gauge is slidably insta