A planar three-degree-of-freedom sliding type loading robot with a multi-unit linear driving function comprises a multi-unit linear driving mechanism, a movable arm lifting mechanism, a bucket control mechanism and the like. Under control of a computer, the multi-unit linear driving mechanism achieves driving of multiple low-power linear drivers and high-power and high-torque power output, and meets the power requirement for the sliding type loading robot. A hydraulic cylinder is applied to the configuration design of the loading robot as a connection rod, through introduction of a hydraulic element, the problem that stress on two driving chains for lifting a movable arm of an original controllable sliding loading mechanism is unbalanced is effectively solved, and the bearing stability is improved. The sliding type loading robot not only has the characteristics of being high in transmission efficiency, high in response speed, high in motion precision, good in controllability and the like as the original controllable sliding loading mechanism, but also has better bearing performance, shock resistance and lifting translation performance through the novel configuration design, can achieve the overload protection function easily and is quite suitable for manufacturing of large, intermediate, and small-sized sliding type loading robots.