Disclosed is an axial-flow type automatic-control threshing machine for salvia hispanica threshing. A top cover is mounted at the upper end of a main cabin, a middle power support is arranged in the middle of the main cabin, a lower power support is arranged in the lower portion of the main cabin, and an inclined discharging plate is arranged between the middle power support and the lower power support. A first transmission shaft is arranged in a drum casing, the upper end of the first transmission shaft is in fit assembly with a first spline socket, and a rotary vane, an upper control springholder and a lower control spring holder are mounted on the first transmission shaft; the lower end of the first transmission shaft is connected with a transmission control spline bushing, and the first transmission shaft is provided with a plurality of floating springs. A second transmission shaft is mounted in the lower power support, the upper end of a transmission control spline shaft is connected with the transmission control spline bushing, and the lower end of the transmission control spline shaft is connected with the second transmission shaft. A motor drives the transmission shaft tofurther drive the drum casing to rotate, and three threshing rods on the drum casing thresh with adjustable threshing force; power is cut off by a power control operating rod, so that accident worsening is avoided effectively.