A pine nut shell opening machine comprises a machine frame, a feeding mechanism, a shell opening mechanism, a discharging hopper and a driver. The feeding mechanism, the shell opening mechanism, the discharging hopper and the driver are arranged on the machine frame. The pine nut shell opening machine is characterized in that the feeding mechanism is a vibration feeding machine, the shell opening mechanism is a pair of pressing rollers, the pressing rollers rotate relatively and are driven by the driver, each pressing roller is provided with a plurality of arc grooves which are arrayed in the axial direction of the pressing roller, the arc grooves in the two pressing rollers are opposite, roller gaps are formed between arc grooves in the two pressing rollers, a discharging end of a feeding hopper is provided with a guiding groove which is provided with a plurality of feeding channels, discharging ends of the feeding channels are provided with a plurality of straightening devices which are used for enabling the tip portions of pine nuts to be downward to enter the pressing roller gaps, the two sides of each pressing roller gap are respectively provided with one straightening device, and the discharging hopper is arranged below the pressing rollers. The problems that feeding is not convenient, production efficiency is low, a production process can be easily stopped, occupied space is large, and using is not convenient are fundamentally solved, and the pine nut shell opening machine has the advantages of being high in automation degree and simple in operation method, energy is saved, environment is protected, noise is low, and shell opening efficiency is high.