The utility model discloses a but simple and easy big -arch shelter telescopic ejector rod, including ejector pin, ejector pin support and bolt, the ejector pin divide into the ejector pin first the one and ejector pin lower half, the ejector pin first the one and the ejector pin lower half pass through screw sleeve threaded connection, first pin joint of ejector pin below the ejector pin support,the ejector pin support pass through the staple bolt and can dismantle with the big -arch shelter crossbeam and be connected. Compared with the prior art, the ejector pin be divided into first one ofejector pin and pass through screw sleeve threaded connection with the ejector pin lower half and pass through the ejector rod base pin joint and below the big -arch shelter crossbeam, can adjust inreal time the ejector pin height through the screw sleeve connected mode, also can upwards fold when the big -arch shelter need not support and pack up the assurance road to simple structure convenient and practical.