According to the present situation that the current road wrecker with a large occupied volume is mainly towed by truck and cannot be applied to car clearing on the congested or narrow road, based on the structure of existing electric pallet truck, a small sized road wrecker is designed, which has some advantages such as small volume, convenient to use and flexible operation. The main structure, hydraulic system and working principle are designed and illustrated in this paper. The optimization design of mechanism multiobjective function for scissors lifting device is carried out by using MATLAB optimization toolbox, and installation position parameters of hydraulic cylinder is optimized by using optimization design concept, which decreases the maximum output force of hydraulic cylinder and reduces the energy consumption of hydraulic system, and provides a reliable basis for the improvement design of this kind of small sized road wrecker.