A blade load mechanism for a blade holder of a microtome, the blade holder having a base defining a blade receptacle configured to receive a blade, the blade load mechanism comprising: a blade supply container configured to contain a blade therein, the blade supply container defining a removal opening through which the blade is able to be removed from the blade supply container, and a blade access slot through an outer wall of the blade supply container in a length direction of the blade; a blade pusher configured to engage with the blade through the blade access slot and slide along the blade access slot to push the blade out of the blade supply container through the removal opening, and deliver the blade into the blade receptacle of the base of the blade holder; a first bracket; a first guide rail fixedly connected to the first bracket; and a first slide block slidable along the first guide rail; wherein the blade pusher is fixedly connected to the first slide block, such that the first slide block is able to be driven to slide along the first guide rail to drive the blade pusher to slide in the blade access slot; the blade load mechanism further comprising: a first electric motor having an output shaft and provided at one of the first slide block and the first bracket; a first gear provided at an end of the output shaft; and a first rack provided at the other of the first slide block and the first bracket and capable of meshing with the first gear; wherein the first bracket comprises a first plate and a second plate, the first plate is perpendicularly connected to a first end of the second plate, the first guide rail and the first gear are fixedly connected to the two opposite sides of the first plate, and the first guide rail is arranged away from the second plate; the first rack is fixedly connected to a first side of the second plate, the blade supply container is detachably connected to a second side of the second plate opposite the first side of the second plate; and wherein the first bracket further comprises a third plate, the third plate is perpendicularly connected to a second end of the second plate opposite the first end of the second plate, the third plate and the first plate are located at two opposite sides of the second plate, and the blade supply container is detachably connected to the third plate. a blade supply container configured to contain a blade therein, the blade supply container defining a removal opening through which the blade is able to be removed from the blade supply container, and a blade access slot through an outer wall of the blade supply container in a length direction of the blade; a blade pusher configured to engage with the blade through the blade access slot and slide along the blade access slot to push the blade out of the blade supply container through the removal opening, and deliver the blade into the blade receptacle of the base of the blade holder; a first bracket; a first guide rail fixedly connected to the first bracket; and a first slide block slidable along the first guide rail; wherein the blade pusher is fixedly connected to the first slide block, such that the first slide block is able to be driven to slide along the first guide rail to drive the blade pusher to slide in the blade access slot; the blade load mechanism further comprising: a first electric motor having an output shaft and provided at one of the first slide block and the first bracket; a first gear provided at an end of the output shaft; and a first rack provided at the other of the first slide block and the first bracket and capable of meshing with the first gear; wherein the first bracket comprises a first plate and a second plate, the first plate is perpendicularly connected to a first end of the second plate, the first guide rail and the first gear are fixedly connected to the two opposite sides of the first plate, and the first guide rail is arranged away from the second plate; the first rack is fixedly connected to a first side of the second plate, the blade supply container is detachably connected to a second side of the second plate opposite the first side of the second plate; and wherein the first bracket further comprises a third plate, the third plate is perpendicularly connected to a second end of the second plate opposite the first end of the second plate, the third plate and the first plate are located at two opposite sides of the second plate, and the blade supply container is detachably connected to the third plate. a first electric motor having an output shaft and provided at one of the first slide block and the first bracket; a first gear provided at an end of the output shaft; and a first rack provided at the other of the first slide block and the first bracket and capable of meshing with the first gear; wherein the first bracket comprises a first plate and a second plate, the first plate is perpendicularly connected to a first end of the second plate, the first guide rail and the first gear are fixedly connected to the two opposite sides of the first plate, and the first guide rail is arranged away from the second plate; the first rack is fixedly connected to a first side of the second plate, the blade supply container is detachably connected to a second side of the second plate opposite the first side of the second plate; and wherein the first bracket further comprises a third plate, the third plate is perpendicularly connected to a second end of the second plate opposite the first end of the second plate, the third plate and the first plate are located at two opposite sides of the second plate, and the blade supply container is detachably connected to the third plate.