The invention discloses a water-soluble particle mixing and stirring mechanical device, comprising a main body box, wherein support legs are arranged at the left and right sides of the lower end of the main body box, a filter is arranged on the right side of the bottom in the main body box, a discharge pipe I is arranged at the lower end of the filter, a motor I is arranged in the middle of the upper end of the main body box, a stirring shaft is arranged at the lower end of the motor I, the lower end of the stirring shaft runs through the main body box and is connected to the bottom in the main body box, a plurality of stirring blades are arranged in the middle of the stirring shaft, and secondary stirring blades are disposed in the middle of the lower ends of the stirring blades. Througha feeding hole, a feeding pipe, a water pump and a water pipe in cooperation, water-soluble particles can be preliminarily dissolved and the fluidity of the water-soluble particles is further increased, which are favorable for further dissolution. The water-soluble particles are ground into fine powder by a fixed grinding disc, a rotating grinding disc, a motor II and a gear in cooperation, and the contact area between the fine powder and water is larger, which is more favorable for dissolution.