The invention provides a left and right machine interchange barrier gate core which comprises a bottom plate, a motor, a speed reducer, a clutch mechanism, a limiting mechanism and a gate bar splint, wherein the bottom plate provides support for the left and right machine interchange barrier gate core; the clutch mechanism is installed at the tail end of the motor; the speed reducer is connected with the motor; an output shaft is arranged on the speed reducer; front and rear sides of the bottom plate are separately provided with a bearing block; the output shaft is installed on the bottom plate through the bearing blocks; the output shaft directly serves as a driving shaft of an external gate bar; the gate bar splint is connected with the output shaft; the gate bar splint is used for being connected with the external gate bar; the limiting mechanism is connected with the output shaft; and the limiting mechanism and the speed reducer are installed at the same side of the bottom plate. The invention also provides a barrier gate adopting the left and right machine interchange barrier gate core. According to the left and right machine interchange barrier gate core and barrier gate provided by the invention, under the condition that a box body is not changed, the left and right machine interchange of the barrier gate can be realized through simple operation steps, thereby being convenient for implementing road management.