The invention relates to a hydraulic aerial cage telescopic boom sliding block mechanism. The hydraulic aerial cage telescopic boom sliding block mechanism is characterized in that in a space formed by an outer arm and an inner arm in the upper and lower direction, a fixed sliding block and an adjustable sliding block are arranged, a combination face of the fixed sliding block and the adjustable sliding block is a slope, a fixing plate vertical to the adjustable sliding block is fixedly connected to the portion, extending out of the end of the outer arm, of the adjustable sliding block, and a flange is arranged at the portion of a port of the outer arm; and a gasket is arranged between the flange and a fixing plate, and the fixing plate, the gasket (5) and the flange are fixed together through two bolts. The hydraulic aerial cage telescopic boom sliding block mechanism has the beneficial effects that gap adjustment is convenient, and the adjusting accuracy is higher; meanwhile, the beneficial effects that sliding faces are good in contact, the bearing capacity is large, parts are not likely to being damaged, the service life is longer, and normal work of equipment can be better guaranteed are achieved.