The invention discloses an automatic feeding mechanism for a titanium and titanium alloy plate shearing machine. The mechanism comprises a support frame and rollers, wherein the support frame comprises four support legs, cross braces, a positioning plate and a support plate; the cross braces are fixed at tops of the support legs; the positioning plates are fixedly connected with the cross braces through a plurality of support plates arranged in parallel; a plurality of driven rollers which are parallel are arranged between every two parallel positioning plates, and two ends of the driven rollers are connected with the positioning plates through roller shafts; a storage box is arranged on one side of the support frame, a driving device is arranged in the storage box, a driving roller is arranged at the top of the storage box, and a transmission shaft of the driving roller is in meshed connection with an output shaft of a driving device, two limit baffles are arranged on two sides of each driven roller, arranged on outer sides of the positioning plates and connected with each other through baffle arms, return springs are arranged at parts, between the two limit baffles, of the corresponding baffle arms, and bolts are arranged at two ends of each baffle arm.