The invention belongs to agricultural equipment, and relates to a soil preparation and pesticide spraying combined machine which comprises a traction frame, a pesticide spraying device, a rack, a pesticide box, a disc harrow set, a lifting oil cylinder, a conveying wheel, a soil crushing roll, a soil crushing and pressing roll frame, a supporting arm and a pressing roll. The pesticide box is arranged on the rack. The pesticide spraying device is arranged on the front portion of the rack, and the disc harrow set, the soil crushing roll and the pressing roll are arranged on the lower portion of the rack. The soil crushing roll and the pressing roll are arranged on the soil crushing and pressing roll frame through bearings, one end of the supporting arm is fixedly connected with the rack, and the other end of the supporting arm is hinged to the soil crushing and pressing roll frame. When the machine works, the pesticide spraying device firstly sprays pesticide on the earth surface, then the disc harrow set carries out soil aeration and soil loosening work, meanwhile, the pesticide and soil are mixed, then the soil is crushed through the soil crushing roll and is further mixed with the pesticide, and finally the soil is pressed by the pressing roll. The soil preparation and pesticide spraying combined machine is adopted for work, the pesticide and the soil can be mixed timely, volatilization losses of the pesticide are avoided, and meanwhile the production rate of the machine is improved.