Supporting device capable of automatically aligning and increasing force

A piston end cover is in threaded connection with the bottom of a thrust piston, a return spring is installed in an inner cavity in the upper portion of the piston end cover, a stop end base is installed on the top of the return spring, a clamping sleeve and a steel ball are installed on the top of the stop end base, and supporting rods are installed in the piston end cover and the clamping sleeve. The supporting rod is located in the return spring, the top of the supporting rod penetrates out of the top of the cylinder body and is in threaded connection with a supporting cap, an ejection spring is installed at the bottom of the supporting cap, an ejection spring seat is installed at the bottom of the ejection spring, the ejection spring seat is in threaded connection with the top of the lifting piston, and the lifting piston is sleeved with a return spring. The return spring is located in a lower inner cavity of the piston end cover. According to the invention, the lifting piston can be used for boosting the