The invention relates to a side protection device for a track-mounted forest fire-fighting armored vehicle. By the adoption of the side protection device for the track-mounted forest fire-fighting armored vehicle, the problems that it is hard to achieve fire-proof protection of side edges of an existing track-mounted armored vehicle, side components of the armored vehicle are prone to being damaged when the existing track-mounted armored vehicle is used for close-range fire fighting, and the personnel safety of an operator of the existing track-mounted armored vehicle is even threatened are solved. The side protection device for the track-mounted forest fire-fighting armored vehicle comprises two protective plate assemblies. Each protective plate assembly comprises a fixed protective plate, a movable protective plate and two hydraulic cylinders. The two fixed protective plates are fixedly mounted at the bottom ends of the two sides of a frame body of the armored vehicle correspondingly. The two sides of the frame body of the armored vehicle are each provided with the two corresponding hydraulic cylinders. The stretching-out end of a piston rod of each hydraulic cylinder is located at the bottom end of the hydraulic cylinder. Each movable protective plate is fixedly connected with the stretching-out ends of the piston rods of the two corresponding hydraulic cylinders, located on the same side, of the armored vehicle. Each hydraulic cylinder communicates with a hydraulic pump of the armored vehicle through a hydraulic pipe. The side protection device is used during forest fire-fighting.